Office of Technology Assessment (June 1975). "Who Owns AGT Systems?". Automated Guideway Transit: An Assessment of PRT and Other New Systems. ISBN978-1-4289-2523-6. Retrieved February 13, 2008.
The United States (June 1975). "The Status and Potential of Automated Guideway Transit in Urban Areas"(PDF). Automated guideway transit : an assessment of PRT and other new systems, including supporting panel reports (Report). United States Congress, Office of Technology Assessment. p. 17. Retrieved February 17, 2021 – via Princeton University.