MLA

McKay, Claude, 1890-1948. Cartier-Bresson, Henri. Box 2, folder 35. 1933-35, n.d.. https://collections.library.yale.edu/catalog/16742347.

APA, 6th edition

McKay, Claude, 1890-1948. (["Box 2, folder 35"])(1933-35, n.d.)[Cartier-Bresson, Henri]. https://collections.library.yale.edu/catalog/16742347.