MLA

Johnston, William Walker Whitehall, 1835-1886. Album Page 5. Verso, bottom: Portrait of a man, possibly Thomas Francis Johnston. Box 1, folder 3. circa 1859. https://collections.library.yale.edu/catalog/10944323.

APA, 6th edition

Johnston, William Walker Whitehall, 1835-1886. (["Box 1, folder 3"])(circa 1859)[Album Page 5. Verso, bottom: Portrait of a man, possibly Thomas Francis Johnston]. https://collections.library.yale.edu/catalog/10944323.