MLA

Rudofsky, Bernard, 1905-1988. [Letter : 1958 January 27, Bernard Rudofsky to Saul Steinberg]. Box 6 | Folder: Correspondence 1959. 1958 [i.e. 1959?] January 27. https://collections.library.yale.edu/catalog/10544419.

APA, 6th edition

Rudofsky, Bernard, 1905-1988. (["Box 6 | Folder: Correspondence 1959"])(1958 [i.e. 1959?] January 27)[[Letter : 1958 January 27, Bernard Rudofsky to Saul Steinberg]]. https://collections.library.yale.edu/catalog/10544419.