MLA

Dellenbaugh, Frederick Samuel, 1853-1935. Kanab Canyon. Box 1, folder 12. n.d.. https://collections.library.yale.edu/catalog/2017574.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 1, folder 12"])(n.d.)[Kanab Canyon]. https://collections.library.yale.edu/catalog/2017574.