SF-137. Trail.
MLA
McClintock, Walter, 1870-1949. SF-137. Trail.. Box 145, folder 7577. undated. https://collections.library.yale.edu/catalog/10453722.
APA, 6th edition
McClintock, Walter, 1870-1949. (["Box 145, folder 7577"])(undated)[SF-137. Trail.]. https://collections.library.yale.edu/catalog/10453722.