MLA

Dellenbaugh, Frederick Samuel, 1853-1935. Arizona. Box 1, folder 2. [1928]. https://collections.library.yale.edu/catalog/2015527.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 1, folder 2"])([1928])[Arizona]. https://collections.library.yale.edu/catalog/2015527.