MLA

Camp, Walter, 1859-1925. Physical fitness: general. Box 62, folder 20 | reel 46U. undated. https://collections.library.yale.edu/catalog/10014909.

APA, 6th edition

Camp, Walter, 1859-1925. (["Box 62, folder 20 | reel 46U"])(undated)[Physical fitness: general]. https://collections.library.yale.edu/catalog/10014909.