MLA

Dellenbaugh, Frederick Samuel, 1853-1935. Glen Canyon. Box 1, folder 8. n.d.. https://collections.library.yale.edu/catalog/2017547.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 1, folder 8"])(n.d.)[Glen Canyon]. https://collections.library.yale.edu/catalog/2017547.