MLA

Dellenbaugh, Frederick Samuel, 1853-1935. Arizona. Box 1, folder 3. 1933 Jul. https://collections.library.yale.edu/catalog/2015528.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 1, folder 3"])(1933 Jul)[Arizona]. https://collections.library.yale.edu/catalog/2015528.