1. Boyd Alan, Under Secretary of Commerce for Transportation, then Secretary of the new Department of Transportation. Interview questions transmitted through his son, Mark Boyd, with responses via email. August 2020.
2. Engel Albrecht (Al), rail transport manager at General Electric, 1960s–1970s. Chairman, High Speed Ground Transportation Association in the 1990s. Phone interviews, email correspondence. August, 2020.
3. Annual Reports on the High Speed Ground Transportation Act of 1965, 1966–1976. National Archives and Records Administration, General Records of the U.S. Department of Transportation, Record Group 398. College Park, MD.
4. Mongini Arrigo, Department of Commerce, Federal Railroad Administration, and Office of High Speed Ground Transportation official from 1960s–2000s. Phone interview. April, 2021.
5. Pell Claiborne (United States Senator). Presidential papers, University of California Santa Barbara: www.presidency.ucsb.edu.