MLA

Plowden, David. Yard Conductor "Pulling Pin", Delaware Hudson Railroad Freight Yard. Mechanicville, New York (D. 1975. https://collections.library.yale.edu/catalog/2041809.

APA, 6th edition

Plowden, D. (1975). Yard Conductor "Pulling Pin", Delaware Hudson Railroad Freight Yard. Mechanicville, New York (D [Gelatin silver prints, Photographic prints, Photographs]. https://collections.library.yale.edu/catalog/2041809.