MLA

McClintock, Walter, 1870-1949. 737. [Sioux Chiefs. Mountain Chief, Blood, and Cream Antelope (Left to Right).]. Box 66, folder 3516. 1935. https://collections.library.yale.edu/catalog/2009356.

APA, 6th edition

McClintock, Walter, 1870-1949. (["Box 66, folder 3516"])(1935)[737. [Sioux Chiefs. Mountain Chief, Blood, and Cream Antelope (Left to Right).]]. https://collections.library.yale.edu/catalog/2009356.