MLA

Carson, Rachel, 1907-1964. Notes and notebooks. Box 1, folder 1. n.d.. https://collections.library.yale.edu/catalog/17410642.

APA, 6th edition

Carson, Rachel, 1907-1964. (["Box 1, folder 1"])(n.d.)[Notes and notebooks]. https://collections.library.yale.edu/catalog/17410642.