MLA

Simpson, Randolph Linsly, 1927-1992. McKecknie & Oswald, Toledo, OH Full length double portrait, small boy and girl; snow scene set, boy in tattered outer coat, both smiling. Cabinet photograph. Box 9, folder 240. circa 1890. https://collections.library.yale.edu/catalog/2002292.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 9, folder 240"])(circa 1890)[McKecknie & Oswald, Toledo, OH Full length double portrait, small boy and girl; snow scene set, boy in tattered outer coat, both smiling. Cabinet photograph]. https://collections.library.yale.edu/catalog/2002292.