Cite

Great Sand Dunes, City of Rocks

MLA

Erdoes, Richard, 1912-2008. Great Sand Dunes, City of Rocks. Box 85 | New Mexico Nature, Flora. 1974-1987, undated. https://collections.library.yale.edu/catalog/2105643.

APA, 6th edition

Erdoes, Richard, 1912-2008. (["Box 85 | New Mexico Nature, Flora"])(1974-1987, undated)[Great Sand Dunes, City of Rocks]. https://collections.library.yale.edu/catalog/2105643.