Cite

[Letter : [1966?], Washington (D.C.), Smithsonian Institution to Saul Steinberg, New York]

MLA

Institution, Smithsonian. [Letter : [1966?], Washington (D.C.), Smithsonian Institution to Saul Steinberg, New York]. 0AD. https://collections.library.yale.edu/catalog/10054689.

APA, 6th edition

Institution, S. (0 C.E.). [Letter : [1966?], Washington (D.C.), Smithsonian Institution to Saul Steinberg, New York] [Correspondence]. https://collections.library.yale.edu/catalog/10054689.