Illuminating the Kingdom Tower in green at night during the celebration on the occasion of winning Expo 2030 in Saudi Arabia, development and economic growth of towers and skyscrapers, cultural performances and recreational activities, a picture from above of modern architectural engineering art.
The urban development and growth of the economic and commercial towers in the city of Riyadh, the architectural art of building facilities, hotels and skyscrapers in the Kingdom, events, celebrations and recreational activities to celebrate the occasion of winning the Expo 2030 exhibition in Saudi Arabia.
Economic development and growth, throwing fireworks in front of the Kingdom Tower illuminated in green at night time during the celebration on the occasion of winning Expo 2030 in Saudi Arabia, cultural shows and entertainment activities, a picture from above of modern architectural engineering art.
Illumination of the King Abdullah Financial Towers at night during the celebration on the occasion of winning the Expo 2030 exhibition in Saudi Arabia, the development and economic growth of the towers and skyscrapers, cultural performances and recreational activities, a picture from above of modern architectural engineering art.
Throwing purple fireworks in front of the Kingdom Tower illuminated in green at night time during the celebration on the occasion of winning the Expo 2030 exhibition in Saudi Arabia, development and economic growth, cultural performances and recreational activities, a picture from above of modern architectural engineering art.
Illuminating the famous economic and commercial towers and skyscrapers to celebrate the occasion of winning Expo 2030 in Saudi Arabia, development and economic growth in the capital, cultural performances, activities and entertainment events in the Kingdom, architectural engineering art in a modern and advanced style.
Illuminating the famous economic and commercial towers and skyscrapers to celebrate the occasion of winning Expo 2030 in Saudi Arabia, development and economic growth in the capital, cultural performances, activities and entertainment events in the Kingdom, architectural engineering art in a modern and advanced style.
Entertainment activities and cultural performances, modern architectural art, growth and economic development of towers and skyscrapers, a picture from above of the illumination of the King Abdullah Financial Towers at night time during the celebration on the occasion of winning Expo 2030 in Saudi Arabia.
Illumination of the King Abdullah Financial Towers at night during the celebration on the occasion of winning the Expo 2030 exhibition in Saudi Arabia, the development and economic growth of the towers and skyscrapers, cultural performances and recreational activities, a picture from above of modern architectural engineering art.
Events, celebrations and entertainment activities to celebrate the occasion of winning the Expo 2030 in Saudi Arabia, air shows and lighting of economic and commercial towers in the city of Riyadh, architectural engineering art for building facilities, hotels and skyscrapers in the Kingdom, urban development and growth
A picture from above of the Riyadh manuscript, the world’s choice, on the Kingdom Tower, illuminated in green at night, during the celebration on the occasion of winning the Expo 2030 exhibition in Saudi Arabia, cultural performances and recreational activities, development and economic growth, modern architectural engineering art.
The Kingdom’s pavilion at Expo 2020 Dubai, Saudi Arabia’s vision at Expo 2020 Dubai in the United Arab Emirates, Creative Arts, National Heritage, International Expo, Making the Future, Tourism in the Emirates
Cultural performances, activities and entertainment events in the Kingdom, modern and advanced architectural art, lighting of famous economic and commercial towers and skyscrapers to celebrate the occasion of winning Expo 2030 in Saudi Arabia, development and economic growth in the capital.
Development and economic growth in the capital, cultural performances, activities and entertainment events in the Kingdom, modern and advanced architectural engineering art, lighting the famous economic and commercial towers and skyscrapers to celebrate the occasion of winning the Expo 2030 exhibition in Saudi Arabia.
Events, celebrations and entertainment activities to celebrate the occasion of winning the Expo 2030 in Saudi Arabia, air shows and lighting of economic and commercial towers in the city of Riyadh, architectural engineering art for building facilities, hotels and skyscrapers in the Kingdom, urban development and growth
Cultural performances and entertainment activities, modern architectural art, growth and economic development of towers and skyscrapers, a picture from above of the illumination of the King Abdullah Financial Towers at night time during the celebration on the occasion of winning the Expo 2030 in Saudi Arabia.
Colored lighting shows on the Kingdom Tower, an artistic journey of creative light transformation, the anniversary of Saudi National Day September 23, enjoying the forms of light arts, the Noor Saudi Arabia festival and event, the seasonal Riyadh Art Program initiative, annual celebrations and events.
Riyadh manuscript, the heart of the world, urban growth and development in the Kingdom, a Saudi future vision, events, celebrations and entertainment activities to celebrate the occasion of winning Expo 2030 in Saudi Arabia, interest in development, growth and achieving Saudi Arabia's goals
Events, celebrations and entertainment activities to celebrate the occasion of winning the Expo 2030 in Saudi Arabia, air shows and lighting of economic and commercial towers in the city of Riyadh, architectural engineering art for building facilities, hotels and skyscrapers in the Kingdom, urban development and growth
A panoramic image of a Saudi business center with huge glass facades, a futuristic imaginative view of the towers, Saudi Vision 2030, urban progress and growth, modern architectural arts and designs for skyscrapers in the Kingdom, towers, buildings and commercial facilities, the concept of project auditing and business supervision
Bahrain Pavilion at the Expo in Dubai, Dubai Expo 2020, Tourism in the Emirates, the distinctive architectural art of Dubai, World Expo 2020, United Arab Emirates, an architectural masterpiece
An aesthetic close-up image from the outside of the dome of Al Wasl Square in the Dubai Expo, a cultural landmark in the heart of the city of creativity, a global architectural masterpiece, a luminous steel dome that gathers under it thousands of people a
Economic development and growth, fireworks display over the towers of Riyadh at night to celebrate Saudi National Day, modern architectural art of skyscrapers, famous tourist places and landmarks in the Kingdom of Saudi Arabia
A Saudi Arabian Gulf girl carrying the flag of the Kingdom of Saudi Arabia, car participation in a festive march on the National Day, the events and activities of the Saudi National Day, the anniversary of the unification of the Kingdom of Saudi Arabia, t
Close-up of the Expo 2020 Dubai gate, Daytime close-up of the entry gate to Dubai Expo 2020, Tourism in the UAE, Dubai's distinctive architectural art, World Expo 2020, United Arab Emirates, architectural masterpiece
Towers, buildings and commercial facilities, urban progress and growth, a panoramic image of a Saudi business center with huge glass facades, an imaginative future view of the towers, Saudi Vision 2030, modern architectural arts and designs for skyscrapers in the Kingdom, the concept of project auditing and business supervision
Developments in health care and medical practices, the introductory showcase at the World Health Exhibition in Riyadh, participation in international exhibitions and conferences in the Kingdom of Saudi Arabia, working to achieve a future vision 2030 for the Saudi medical sector
Night view of the King Abdullah Financial District (CAFD) in Riyadh, Saudi Arabia, the towers are lit in green, the celebration of the Saudi National Day, the identity of the Saudi National Day 92, the famous tourist attractions of Riyadh, the economic an
NEOM exhibition of future city design models “The Line” in Riyadh, visual displays, engineering and architectural techniques, learning about the future of urban communities, global developments in innovative designs, cities in harmony with nature, a Saudi future vision 2030
Economic development and growth, fireworks display over the towers of the city of Riyadh at night, modern architectural art of skyscrapers, famous places and tourist attractions in the Kingdom of Saudi Arabia
Economic development and growth, fireworks display over the towers of the city of Riyadh at night, modern architectural art of skyscrapers, famous places and tourist attractions in the Kingdom of Saudi Arabia
Interior decorations in the exhibition sections, a Saudi Gulf Arab man standing in front of the “The Line” logo in Riyadh with thinking gestures, architectural planning for the real estate sector, future innovations in the infrastructure of smart cities, a future Saudi vision 2030, building an advanced civilized future in the Kingdom
Models and designs of the city of the future “The Line” in Riyadh, introductory electronic screens at the NEOM exhibition, a Saudi future vision 2030, learning about the future of urban communities, global developments in innovative designs, visual displays, and engineering and architectural techniques.
High-rise buildings, towers and commercial facilities illuminated at night, Saudi Vision 2030, the concept of architectural engineering development in the city of Riyadh, modern engineering designs and arts for skyscrapers in Saudi Arabia, an imaginary future view of urban progress and growth
Commemorating the date of the unification of Saudi Arabia, September 23, Saudi National Day, celebrating Flag Day, March 11, a picture from the back of a Saudi-Gulf Arab engineer wearing a helmet and protection vest and holding the Kingdom’s flag, standing in front of the distinguished towers of Riyadh, the nation’s renaissance thanks to its sons
Raising the banner of monotheism and Islam, Saudi National Day, Founding Day, February 22, Flag Day, March 11, anniversary of the unification of the Kingdom, Rabi’ al-Awwal 8, pride in the nation’s achievements, a Saudi Gulf Arab man and woman standing in outer space in front of the planet Earth.
Working to achieve the goals of the Ministry of Health, innovations and strategies for health care at the World Health Exhibition in Riyadh in the Kingdom of Saudi Arabia, events, activities and activities in exhibitions and conferences, keeping pace with developments to enhance a Saudi future vision 2030
The largest gathering of health care workers in the Kingdom of Saudi Arabia, the Riyadh interface for exhibitions and conferences, communication, trading and the experts’ forum at the World Health Exhibition in the capital, places and regions prepared for tourist attraction, achieving a future vision 2030 for the Saudi medical sector
The architectural engineering art of buildings and facilities in the capital, pride in belonging to the national identity, a close-up of the Kingdom Tower building lit in green in the city of Riyadh, Saudi Arabia at night time, Saudi National Day celebrations on September 23, Saudi Foundation Day activities on February 22
A Saudi Arabian Gulf man kisses the flag of Saudi Arabia, towers and skyscrapers, King Abdullah Financial Center (KAFD) in Riyadh, the anniversary of the establishment of the Saudi state, the identity of the Saudi National Day 92, Saudi tourist attraction
Achieving the industrial revolution, a future vision for the Kingdom of Saudi Arabia, the concept of cultural development in the Kingdom, rebuilding cities in a modern and advanced technological manner, building a civilized and advanced future, Saudi industrial development and progress.
Paying attention to afforestation and irrigation water projects, the Green Riyadh Pavilion at the Cityscape International Exhibition, a future Saudi vision 2030, enhancing economic efficiency and achieving environmental sustainability, the Riyadh Exhibition Center in the town of Mulham in Saudi Arabia, increasing green spaces and raising the quality of life.
A huge colorful dome at the World Expo 2020 in Dubai in the United Arab Emirates, Russia 2020 Pavilion, distinctive architectural art, tourism in the Emirates
Establishing feelings of love and loyalty to the Saudi state, Unity Day and the modern history of the Kingdom, Celebration of the 93rd Saudi National Day, National Day on 8 Rabi` al-Awwal, A Saudi Arab Gulf woman wearing abaya and hijab celebrates Flag Da
The future vision of Saudi Arabia 2030, a picture from behind of Saudi Gulf Arab children standing in front of a picture of King Salman bin Abdulaziz, celebrating Saudi National Day, September 23, Flag Day, March 11, pride and pride in belonging to the Kingdom
Waterfront design model in coastal cities, Saudi future vision 2030, learning about the future of urban communities, global developments in innovative designs, NEOM exhibition of models and models of future city designs “The Line” in Riyadh, visual displays and engineering and architectural techniques
Saudi Vision 2030, the concept of architectural engineering development in the city of Riyadh, tall buildings, towers and commercial facilities illuminated at night, modern engineering designs and arts for skyscrapers in Saudi Arabia, an imaginary future view of progress and urban growth
Initiatives and investment in the health sector, major medical projects, innovations and strategies for health care at the World Health Exhibition in Riyadh in the Kingdom of Saudi Arabia, events, events and activities in exhibitions and conferences, keeping pace with development to enhance a Saudi future vision 2030
Anniversary of the unification of the Kingdom, Rabi’ al-Awwal 8, gestures of pleasure and pride in the nation’s achievements, a close-up portrait of a Saudi Gulf Arab man wearing a shemagh and traditional thobe carrying the Saudi flag, Flag Day, March 11, loyalty to the nation by celebrating the Saudi National Day
National Day to commemorate the unification of Saudi Arabia, commemorating the date of the National Day, September 23, celebrating Flag Day, March 11, a picture from behind of a Saudi-Gulf Arab engineer wearing a helmet and a protective vest, holding the Kingdom’s flag and standing in front of the distinguished towers and skyscrapers of Riyadh, the nation’s renaissance thanks to its sons
Saudi Noor event and festival, an aerial photo of the colorful lighting displays on the Kingdom’s towers, the Riyadh Art seasonal program initiative, fun entertainment activities, an artistic journey for creative light transformation, annual national events and celebrations, enjoying the forms of light arts
Interest in planting trees and green plants, archaeological entertainment places during the day, mud structures built in the old style, authentic Saudi Arabian civilization, enjoying the famous tourist attractions, Al-Bujairi Overlook and Park in the Diriyah neighborhood in the city of Riyadh.
Models of ships and luxury yachts in the water, NEOM exhibition of models of future city designs “The Line” in Riyadh, visual displays and engineering and architectural techniques, future innovations in the infrastructure of smart cities, a future Saudi vision 2030, sustainability and architectural planning for the real estate sector
The historic Diriyah development project, mud walls built in the old style, tourist areas and authentic Saudi Arabian civilization, enjoying the famous tourist attractions, archaeological entertainment places during the day, Al-Bujairi Overlook and Park in the Diriyah neighborhood in the city of Riyadh
Events, activities and activities in exhibitions and conferences and working on health investment, health care innovations at the World Health Exhibition in Riyadh in the Kingdom of Saudi Arabia, keeping pace with developments to enhance a Saudi future vision 2030
Cultural performances, activities and entertainment events in the Kingdom, modern and advanced architectural art, lighting of famous economic and commercial towers and skyscrapers to celebrate the occasion of winning Expo 2030 in Saudi Arabia, development and economic growth in the capital.
A cultural tourist center in Al-Bujairi Park, celebrating National Day on September 23 in the Jewel of the Kingdom, popular archaeological buildings in the heritage village, the ancient walls of Diriyah in the city of Riyadh, Saudi founding day 1727 AD, Saudi landmarks in the historic Al-Turaif neighborhood
Commemoration of the Saudi National Day and Day, commemoration of the Saudi Flag Day, March 11, a smiling, veiled Saudi Gulf Arab woman wearing the black abaya and carrying the Saudi flag with pride and honor, celebrating the unification of the Kingdom at the hands of King Abdulaziz 8 Rabi’ al-Awwal, background of the towers of the city of Riyadh
A corner from the back of a Saudi Arabian Gulf woman carrying the flag of the Kingdom of Saudi Arabia in the desert areas, the logo is our home, the anniversary of the establishment of the Saudi state, cover design, the identity of the Saudi National Day
Future innovations in smart city infrastructure, models of ships and luxury yachts in the water, NEOM exhibition of models of future city designs “The Line” in Riyadh, visual displays and engineering and architectural techniques, future Saudi vision 2030, sustainability and architectural planning for the real estate sector
Architectural engineering art and advanced design of towers and skyscrapers, famous landmarks and tourist places in the Kingdom of Saudi Arabia, attracting foreign tourists, modern urban growth and progress, Saudi Vision 2030, view of the city of Riyadh illuminated at night
An imaginative future view of urban progress and growth, modern architectural arts and designs for skyscrapers in the Kingdom of Saudi Arabia, towers, buildings and high-rise commercial facilities, a Saudi future vision 2030, the concept of architectural engineering development in the city of Riyadh.
Popular costume of the central region, celebrations of national occasions, commemoration of the Saudi National Day September 23, the day of the founding of the first Saudi state in 1727 AD, a close-up of a smiling Saudi Arab man wearing the Dakla and Ghutra on the National Day looking at the camera, a background of illuminated skyscrapers at night
Keeping pace with development to promote a future Saudi vision 2030, providing educational services and working to achieve the goals of the Ministry of Health, health care innovations at the World Health Exhibition in Riyadh in the Kingdom of Saudi Arabia, events, events and activities at exhibitions and conferences
Saudi National Day September 23, a Saudi Gulf Arab man wearing a white thobe and shemagh and carrying the Saudi flag, the concept of patriotism, celebrating the National Day for the unification of the Kingdom, Flag Day March 11, urban growth and development in Riyadh, background of towers and skyscrapers
Discussions and dialogues on developing environmental sustainability in the field of civil aviation, visitors from all over the world gather at the Future of Aviation Conference in Riyadh, Saudi Arabia, famous cultural events and seminars, Saudi Vision 2030
Day of unity and the modern history of the Kingdom, embodying feelings of love and loyalty, celebrating the Saudi National Day 8 Rabi’ al-Awwal, a veiled Saudi Gulf Arab woman wearing the abaya and holding the Kingdom’s flag with pride and appreciation, Saudi Flag Day March 11, background of the Kafed Towers in Riyadh
National Day commemorating the unification of Saudi Arabia, commemorating the date of the Saudi National Day, September 23, celebrating Flag Day, March 11, a picture from behind of a Saudi-Gulf Arab engineer wearing a helmet and protection vest, holding the Kingdom’s flag and standing in front of the distinguished towers of Riyadh, the nation’s renaissance thanks to its sons
Traditional national occasions, the Hijazi Ardha band looks at something, Saudi popular folklore, wearing the traditional duklah and bra, Saudi Flag Day, March 11, celebrating the anniversary of National Day on Rabi’ al-Awwal 8, strengthening the Queen’s national identity, background of Salwa Palace in Diriyah
The architectural engineering art of Jeddah Port Lighthouse on the Red Sea coast, the waterfront in the Kingdom of Saudi Arabia, the famous Islamic port, tourist places and attractions, future vision 2030
Celebrating the Saudi Flag Day on March 11, commemorating the Saudi National Day on the 8th of Rabi’ al-Awwal, a close-up of the Hijazi Ardha band and folk dancing with swords in front of the National Historical Museum in Riyadh, wearing the popular Dakla and Farmeela costume, traditional folklore on national occasions.
Saudi urban progress and development, achieving a future Saudi vision 2030, building a civilized and advanced future, an aerial photo of the towers and skyscrapers in the city of Riyadh in Saudi Arabia, the construction of modern, advanced technological cities, the definition of urban development in the Kingdom
Architectural engineering art and advanced design for offices in Saudi Arabia, distinctive modern exterior decorations and designs in a modern style, huge glass facades, attracting visitors and tourists from all over the world, urban growth and progress in Riyadh, interest in planting trees on the sides of roads
Buildings and towers in the city of Riyadh in broad daylight, commemorating the Saudi flag March 11, celebrating the unification of the Kingdom, commemorating National Day September 23, a smiling veiled Saudi Arabian Gulf woman wearing the black abaya carrying the Kingdom’s flag with respect and appreciation
Commemoration of the Eid and the Saudi National Day on September 23, a close-up photo of the Hijazi Ardha band and folk dancing with swords in front of the National Historical Museum in Riyadh, wearing the popular Dakla and Farmila costume, traditional folklore on national occasions, celebrating Saudi Flag Day on March 11
National Day on Rabi’ al-Awwal 8, pride in the nation’s achievements and culture, feelings of love and belonging to Saudi Arabia, Science Day March 11, a Saudi Gulf Arab man and woman wearing traditional Saudi dress celebrating the unification of the kingdom, background of the famous Riyadh towers
Participation of the Kingdom’s women in its urban development, commemoration of the Saudi National Day, September 23, a picture from behind of a veiled Saudi Arabian Gulf engineer wearing a helmet and protection vest, holding the Kingdom’s flag in broad daylight, celebrating Flag Day, March 11, background of the towers of the city of Riyadh
Contribution of the nation’s people to urban development, Flag Day, March 11, celebration of the Saudi National Day, September 23, a Saudi Gulf Arab engineer wearing a work jacket and a white protective helmet on National Day and holding the Kingdom’s flag in his hand, a background of the illuminated towers and skyscrapers at night in Riyadh.
Urban progress and growth, a panoramic image of a Saudi business center with huge glass facades, an imaginative future view of the towers, Saudi Vision 2030, modern architectural arts and designs for skyscrapers in the Kingdom, towers, buildings and commercial facilities, the concept of project auditing and business supervision
Commemoration of the National Day, Rabi’ al-Awwal 8, a picture from the back of a veiled Saudi Gulf Arab woman wearing the abaya and carrying the flag of the Kingdom and standing in front of the towers and skyscrapers of Riyadh, Saudi Flag Day, March 11, the Saudi National Day, landmarks of the city of Riyadh at sunrise
Saudi Flag Day, March 11, embodying feelings of love and loyalty, Day of Unity and the modern history of the Kingdom, celebration of the Saudi National Day, National Day on Rabi’ al-Awwal 8, a veiled Saudi Gulf Arab woman wearing the abaya and holding the Kingdom’s flag with pride and appreciation, background of the Kafed Towers in Riyadh
Establishment of the first Saudi state in 1727 AD, Flag Day, March 11, costumes for celebrations of national occasions, anniversary of the Saudi National Day, September 23, a picture from the back of a Saudi Gulf man wearing the Dakla and Ghutra on the National Day, holding the Kingdom’s flag in his hand, standing in front of the illuminated towers of Riyadh at night.
Archaeological entertainment places at sunset, the historic neighborhoods of Diriyah, mud walls built in the old style, tourist areas and authentic Saudi Arabian civilization, enjoying the famous tourist attractions, Al-Bujairi Overlook and Park in the Diriyah neighborhood in the city of Riyadh.
Famous cultural conferences and events, Saudi Vision 2030, visitors from all over the world attending the Future of Aviation Conference in Riyadh, Saudi Arabia, participation of experts and leaders of global companies, promoting innovation, sustainable air transport and cultural exchange
The slogan “Dream is reality and ambition is determination”, a Saudi future vision 2030, a Saudi Arabian Gulf astronaut dressed as astronauts carrying the identity flag for the 93rd Saudi National Day, achieving growth and development in the space sector, remembering the National Day on September 23, the background of towers and skyscrapers
Urban growth and development in Saudi Arabia, a veiled Saudi Gulf Arab woman wearing an abaya and carrying the flag of the Kingdom, gestures of pride and pride in the nation, Flag Day March 11, National Day for the Unification of Saudi Arabia, National Day September 23, Sunrise background on the Riyadh towers
Flag Day, March 11, commemoration of the Saudi National Day, Rabi’ al-Awwal 8, urban development at the hands of the nation’s people, a close-up photo of a smiling Saudi Gulf Arab engineer wearing a work jacket and a white protective helmet on National Day and carrying the Kingdom’s flag, a background of illuminated skyscrapers at night in Riyadh
Celebrating National Day on September 23 in the Jewel of the Kingdom, the ancient walls of Diriyah in the city of Riyadh, a cultural and tourist center in Al-Bujairi Park, popular archaeological buildings in the heritage village, Saudi Founding Day 1727 AD, Saudi landmarks in the historic Turaif neighborhood.
Commemorating the Saudi National Day, the role of Saudi female engineers in urban development, celebrating the unification of the Kingdom on Rabi’ al-Awwal 8, a veiled Saudi Gulf Arab engineer wearing a helmet and protective vest holding the Saudi flag in her hand, Flag Day March 11, background of the King Abdullah Financial Center in broad daylight
Urban development and progress in the country, towers and skyscrapers in the cities of the Kingdom of Saudi Arabia, the anniversary of the National Day on September 23, the symbol, slogan and identity of the country, pride and honor in the country's achievements, celebrating Saudi Flag Day on March 11
Towers, buildings and high-rise commercial facilities during the day, modern architectural designs and engineering arts of skyscrapers in the Kingdom of Saudi Arabia, a futuristic imaginary view of urban progress and growth, Saudi Vision 2030, the concept of architectural engineering development in the city of Riyadh
Modern urban growth and progress, Saudi Vision 2030, a view of Riyadh illuminated at night, architectural engineering art and advanced design of towers and skyscrapers, famous landmarks and tourist places in the Kingdom of Saudi Arabia, attracting foreign tourists
Harmony of cities with green nature, NEOM exhibition of future city design models “The Line” in Riyadh, visual displays and engineering and architectural techniques, learning about the future of urban communities, global developments in innovative designs, a Saudi future vision 2030
Enhancing economic efficiency and achieving environmental sustainability, paying attention to afforestation and irrigation water projects, visitors to the green Riyadh pavilion at the Cityscape International Exhibition, a future Saudi vision 2030, the Riyadh Exhibition Center in the town of Mulham in Saudi Arabia, increasing green spaces and raising the quality of life.
Architectural engineering art in towers and skyscrapers in Riyadh, a picture from the back of a Saudi Gulf Arab man wearing traditional clothing and raising the Saudi flag, commemoration of Saudi National Day, Saudi Flag Day March 11, National Day September 23, background of the King Abdullah Financial Center CAFD
Saudi future vision 2030, learning about the future of urban communities, global developments in innovative designs, harmony of cities with green nature, NEOM exhibition of models and models of future city designs “The Line” in Riyadh, visual displays and engineering and architectural techniques.