MLA

Simpson, Randolph Linsly, 1927-1992. Studio unknown Three quarter length portrait young man seated wearing three-piece suit and hat, holding violin and bow. Cased in green fabric. Tintype, sixth plate. Box 7, folder 139. circa 1870. https://collections.library.yale.edu/catalog/2002203.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 7, folder 139"])(circa 1870)[Studio unknown Three quarter length portrait young man seated wearing three-piece suit and hat, holding violin and bow. Cased in green fabric. Tintype, sixth plate]. https://collections.library.yale.edu/catalog/2002203.