MLA

Simpson, Randolph Linsly, 1927-1992. Unknown photographer Bust portrait, young boy with boutonniere. Cased tintype, gem tintype case, sixteenth plate. Box 6, folder 76. undated. https://collections.library.yale.edu/catalog/2002133.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 6, folder 76"])(undated)[Unknown photographer Bust portrait, young boy with boutonniere. Cased tintype, gem tintype case, sixteenth plate]. https://collections.library.yale.edu/catalog/2002133.