Cite

"Early Plains Wars, Gratian, Sully, Mankato, Etc."

MLA

Erdoes, Richard, 1912-2008. "Early Plains Wars, Gratian, Sully, Mankato, Etc.". Box 45. 1976, undated. https://collections.library.yale.edu/catalog/10256186.

APA, 6th edition

Erdoes, Richard, 1912-2008. (["Box 45"])(1976, undated)["Early Plains Wars, Gratian, Sully, Mankato, Etc."]. https://collections.library.yale.edu/catalog/10256186.