MLA

Simpson, Randolph Linsly, 1927-1992. Unknown photographer Half length portrait of Jessie Morley; young man seated, with long hair curled on one side, wearing a three piece suit with flowing black tie. Sixth plate, Ambrotype. Box 3, folder 42. undated. https://collections.library.yale.edu/catalog/2002062.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 3, folder 42"])(undated)[Unknown photographer Half length portrait of Jessie Morley; young man seated, with long hair curled on one side, wearing a three piece suit with flowing black tie. Sixth plate, Ambrotype]. https://collections.library.yale.edu/catalog/2002062.