MLA

Dellenbaugh, Frederick Samuel, 1853-1935. Grand Canyon. Box 2, folder 69. 1929. https://collections.library.yale.edu/catalog/2017921.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 2, folder 69"])(1929)[Grand Canyon]. https://collections.library.yale.edu/catalog/2017921.