MLA

Erdoes, Richard, 1912-2008. Sky Rainbow. Box 86 | New Mexico Nature, Flora. 1973-1992, undated. https://collections.library.yale.edu/catalog/2106190.

APA, 6th edition

Erdoes, Richard, 1912-2008. (["Box 86 | New Mexico Nature, Flora"])(1973-1992, undated)[Sky Rainbow]. https://collections.library.yale.edu/catalog/2106190.