MLA

Dellenbaugh, Frederick Samuel, 1853-1935. Yosemite. Box 2, folder 48-49. 1921, n.d.. https://collections.library.yale.edu/catalog/2017859.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 2, folder 48-49"])(1921, n.d.)[Yosemite]. https://collections.library.yale.edu/catalog/2017859.