MLA

Steinberg, Saul, 1914-1999. Labyrinth: Leningrad. Box 536 (Oversize), folder 7221. 1956. https://collections.library.yale.edu/catalog/16855259.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 536 (Oversize), folder 7221"])(1956)[Labyrinth: Leningrad]. https://collections.library.yale.edu/catalog/16855259.