MLA

Simpson, Randolph Linsly, 1927-1992. Mezzo-Tint Studio, Washington, D.C. Three quarter length double portrait. Couple, man stands to left, lady seated on right. Cabinet photograph. Box 9, folder 182. circa 1875. https://collections.library.yale.edu/catalog/2002234.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 9, folder 182"])(circa 1875)[Mezzo-Tint Studio, Washington, D.C. Three quarter length double portrait. Couple, man stands to left, lady seated on right. Cabinet photograph]. https://collections.library.yale.edu/catalog/2002234.