MLA

Gabo, Naum, 1890-1977. Schawinsky, Xanti. Box 24. 1939-1980. https://collections.library.yale.edu/catalog/2055184.

APA, 6th edition

Gabo, Naum, 1890-1977. (["Box 24"])(1939-1980)[Schawinsky, Xanti]. https://collections.library.yale.edu/catalog/2055184.