Cite

[Self-portrait pencil drawing by Eric Knight.]

MLA

Knight, Eric, 1987-1943. [Self-portrait pencil drawing by Eric Knight.]. Folder 306. [1931]. https://collections.library.yale.edu/catalog/2008030.

APA, 6th edition

Knight, Eric, 1987-1943. (["Folder 306"])([1931])[[Self-portrait pencil drawing by Eric Knight.]]. https://collections.library.yale.edu/catalog/2008030.