MLA

Simpson, Randolph Linsly, 1927-1992. Unknown photographer Full length, two young men with straw hats, seated beside each other. Cased tintype, sixth plate. Box 6, folder 80. undated. https://collections.library.yale.edu/catalog/2002137.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 6, folder 80"])(undated)[Unknown photographer Full length, two young men with straw hats, seated beside each other. Cased tintype, sixth plate]. https://collections.library.yale.edu/catalog/2002137.