Rogoff, David (May 1961). "The Fourth Ave. Subway". New York Division Bulletin. Electric Railroaders' Association: 2–10. Retrieved May 8, 2017.
erausa.org
Rogoff, Dave (February 1969). "BMT Broadway Subway Platform Extensions"(PDF). New York Division Bulletin. 12 (1). Electric Railroaders' Association: 4. Archived from the original(PDF) on September 15, 2020. Retrieved April 13, 2023.
Rogoff, Dave (February 1969). "BMT Broadway Subway Platform Extensions"(PDF). New York Division Bulletin. 12 (1). Electric Railroaders' Association: 4. Archived from the original(PDF) on September 15, 2020. Retrieved April 13, 2023.