MLA

Gabo, Naum, 1890-1977. Benjamin, Walter. Box 2. 1939-1980. https://collections.library.yale.edu/catalog/2042179.

APA, 6th edition

Gabo, Naum, 1890-1977. (["Box 2"])(1939-1980)[Benjamin, Walter]. https://collections.library.yale.edu/catalog/2042179.