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 May 22, 2020.
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 May 22, 2020.