MLA

Erdoes, Richard, 1912-2008. Cheyenne Children Powwow Drums. Box 75 | Sioux Ceremonies 2, Cheyennes. undated. https://collections.library.yale.edu/catalog/2098760.

APA, 6th edition

Erdoes, Richard, 1912-2008. (["Box 75 | Sioux Ceremonies 2, Cheyennes"])(undated)[Cheyenne Children Powwow Drums]. https://collections.library.yale.edu/catalog/2098760.