MLA

Lipps, Oscar H, United States. Office of Indian Affair, Valentine, Robert G. (Robert Grosvenor), 1872-191. Progress. [1910?]. https://collections.library.yale.edu/catalog/2068092.

APA, 6th edition

Lipps, Oscar H, & United States. Office of Indian Affair, & Valentine, Robert G. (Robert Grosvenor), 1872-191. ([1910?])[Progress]. https://collections.library.yale.edu/catalog/2068092.