MLA

Erdoes, Richard, 1912-2008. "Shells, Beach, Ocean". Box 77. 1973, undated. https://collections.library.yale.edu/catalog/2100088.

APA, 6th edition

Erdoes, Richard, 1912-2008. (["Box 77"])(1973, undated)["Shells, Beach, Ocean"]. https://collections.library.yale.edu/catalog/2100088.