Cite

Knopf, Alfred A., Sr., at the Knopf family home, Purchase, New York

MLA

Van Vechten, Carl, 1880-1964. Knopf, Alfred A., Sr., at the Knopf family home, Purchase, New York. Box 357, folder 4869. 1940 September 12. https://collections.library.yale.edu/catalog/2055000.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 357, folder 4869"])(1940 September 12)[Knopf, Alfred A., Sr., at the Knopf family home, Purchase, New York]. https://collections.library.yale.edu/catalog/2055000.