MLA

Steinberg, Saul, 1914-1999. Robert Delpire Editeur. Box 57, folder 1027. 1958–1965. https://collections.library.yale.edu/catalog/10544401.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 57, folder 1027"])(1958–1965)[Robert Delpire Editeur]. https://collections.library.yale.edu/catalog/10544401.