MLA

Dellenbaugh, Frederick Samuel, 1853-1935. Grand Canyon. Box 2, folder 55. [1910]. https://collections.library.yale.edu/catalog/2017889.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 2, folder 55"])([1910])[Grand Canyon]. https://collections.library.yale.edu/catalog/2017889.