1. Beresnevicius, R. (2019). Defining Urban Travel in 1950s: The Story of New York Airways, Aerotime Hub.
2. Joint, D.-N. (1970). Concepts Studies for Future Intracity Air Transportation Systems, Massachusetts Institute of Technology.
3. Rohacs, J. (2002, January 8–13). PATS. Proceedings of the 23rd International Congress of Aeronautical Sciences, Toronto, ON, Canada.
4. (2020, November 10). NASA Embraces Urban Air Mobility, Calls for Market Study, Available online: https://www.nasa.gov/aero/nasaembraces-urban-air-mobility.
5. (2021, November 13). Uber Elevate|the Future of Urban Air Transport. Available online: https://www.uber.com/info/elevate/.