MLA

Dellenbaugh, Frederick Samuel, 1853-1935. California. Box 4, folder 131. 1934 Sep. https://collections.library.yale.edu/catalog/2025201.

APA, 6th edition

Dellenbaugh, Frederick Samuel, 1853-1935. (["Box 4, folder 131"])(1934 Sep)[California]. https://collections.library.yale.edu/catalog/2025201.