MLA

Simpson, Randolph Linsly, 1927-1992. Studio unknown Three quarter length portrait, young man seated in vest and shirt sleeves. Tintype, sixth plate. Box 7, folder 116. circa 1880. https://collections.library.yale.edu/catalog/2002172.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 7, folder 116"])(circa 1880)[Studio unknown Three quarter length portrait, young man seated in vest and shirt sleeves. Tintype, sixth plate]. https://collections.library.yale.edu/catalog/2002172.