SF-13. Forest Trail. Two White Pines.
MLA
McClintock, Walter, 1870-1949. SF-13. Forest Trail. Two White Pines.. Box 145, folder 7455. undated. https://collections.library.yale.edu/catalog/10453599.
APA, 6th edition
McClintock, Walter, 1870-1949. (["Box 145, folder 7455"])(undated)[SF-13. Forest Trail. Two White Pines.]. https://collections.library.yale.edu/catalog/10453599.