MLA

Dellenbaugh, Frederick Samuel, 1853-1935. Kanab Canyon. Box 2, folder 74. n.d.. https://collections.library.yale.edu/catalog/2017930.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 2, folder 74"])(n.d.)[Kanab Canyon]. https://collections.library.yale.edu/catalog/2017930.