MLA

Pratt, Richard Henry, 1840-1924. (7) Prisoners entering Fort Sill. Box 31. 1862-1972. https://collections.library.yale.edu/catalog/2001762.

APA, 6th edition

Pratt, Richard Henry, 1840-1924. (["Box 31"])(1862-1972)[(7) Prisoners entering Fort Sill]. https://collections.library.yale.edu/catalog/2001762.