MLA

Steinberg, Saul, 1914-1999. Lindey, Alexander, 1896-1981. Box 56, folder 1020. 1963–1972. https://collections.library.yale.edu/catalog/10034287.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 56, folder 1020"])(1963–1972)[Lindey, Alexander, 1896-1981]. https://collections.library.yale.edu/catalog/10034287.