MLA

Carson, Rachel, 1907-1964. "How About Citizenship Papers for the Starling?" Nature Magazine. Box 96, folder 1727. 1939 Jun-Jul. https://collections.library.yale.edu/catalog/2054488.

APA, 6th edition

Carson, Rachel, 1907-1964. (["Box 96, folder 1727"])(1939 Jun-Jul)["How About Citizenship Papers for the Starling?" Nature Magazine]. https://collections.library.yale.edu/catalog/2054488.