MLA
Key, J. L. 1888. Oxford College Library (Oxford, Ga.), Box 3, Folder 20. https://digital.library.emory.edu/purl/494vhhmhqg-cor.
APA, 6th edition
Key, J. L. (Box 3, Folder 20). (1888). [Black-and-white photographs]. Oxford College Library (Oxford, Ga.). https://digital.library.emory.edu/purl/494vhhmhqg-cor.
Chicago
“Key, J. L.” Black-and-white photographs. Early Emory College Photographs, 1888. Box 3, Folder 20. Oxford College Library (Oxford, Ga.). https://digital.library.emory.edu/purl/494vhhmhqg-cor.