MLA

Erdoes, Richard, 1912-2008. "Pine Ridge Winter". Box 42. 1970, undated. https://collections.library.yale.edu/catalog/2108665.

APA, 6th edition

Erdoes, Richard, 1912-2008. (["Box 42"])(1970, undated)["Pine Ridge Winter"]. https://collections.library.yale.edu/catalog/2108665.