SF-31. Canadian Rockies.
MLA
McClintock, Walter, 1870-1949. SF-31. Canadian Rockies.. Box 145, folder 7473. undated. https://collections.library.yale.edu/catalog/10453616.
APA, 6th edition
McClintock, Walter, 1870-1949. (["Box 145, folder 7473"])(undated)[SF-31. Canadian Rockies.]. https://collections.library.yale.edu/catalog/10453616.