MLA

Erdoes, Richard, 1912-2008. Plains Day Dances. Box 51 | Plains Dances, Rodeos, Old Photographs. 1971-1977, undated. https://collections.library.yale.edu/catalog/2081329.

APA, 6th edition

Erdoes, Richard, 1912-2008. (["Box 51 | Plains Dances, Rodeos, Old Photographs"])(1971-1977, undated)[Plains Day Dances]. https://collections.library.yale.edu/catalog/2081329.