MLA

Carson, Rachel, 1907-1964. "Silent Spring." True Magazine. Box 60, folder 1069. 1963 Apr. https://collections.library.yale.edu/catalog/2026582.

APA, 6th edition

Carson, Rachel, 1907-1964. (["Box 60, folder 1069"])(1963 Apr)["Silent Spring." True Magazine]. https://collections.library.yale.edu/catalog/2026582.