MLA

Erdoes, Richard, 1912-2008. Unmounted Slides. Box 87. circa 1970-1990, undated. https://collections.library.yale.edu/catalog/2106967.

APA, 6th edition

Erdoes, Richard, 1912-2008. (["Box 87"])(circa 1970-1990, undated)[Unmounted Slides]. https://collections.library.yale.edu/catalog/2106967.