MLA

Dellenbaugh, Frederick Samuel, 1853-1935. California. Box 1, folder 27. 1921. https://collections.library.yale.edu/catalog/2017632.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 1, folder 27"])(1921)[California]. https://collections.library.yale.edu/catalog/2017632.