MLA

Simpson, Randolph Linsly, 1927-1992. Studio unknown Three quarter length portrait, lady standing in elaborate dress, brimmed straw hat with band. Tintype, sixth plate. Box 7, folder 99. circa 1890. https://collections.library.yale.edu/catalog/2002156.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 7, folder 99"])(circa 1890)[Studio unknown Three quarter length portrait, lady standing in elaborate dress, brimmed straw hat with band. Tintype, sixth plate]. https://collections.library.yale.edu/catalog/2002156.