MLA

Stenzel, Franz (1906-1998). "Swells monument at Neeah Bay near Webster's Point. Swell killed March 1st 1861. Monument built and completed Apr. 1861." Pencil drawing with wash, 18.2 x 12.9 cm.. Box 7, folder 138. [1861]. https://collections.library.yale.edu/catalog/2003208.

APA, 6th edition

Stenzel, Franz (1906-1998). (["Box 7, folder 138"])([1861])["Swells monument at Neeah Bay near Webster's Point. Swell killed March 1st 1861. Monument built and completed Apr. 1861." Pencil drawing with wash, 18.2 x 12.9 cm.]. https://collections.library.yale.edu/catalog/2003208.