MLA

Carson, Rachel, 1907-1964. Hargraves, Malcolm M. (Mayo Clinic). Box 43, folder 794-95. 1958-62. https://collections.library.yale.edu/catalog/17145177.

APA, 6th edition

Carson, Rachel, 1907-1964. (["Box 43, folder 794-95"])(1958-62)[Hargraves, Malcolm M. (Mayo Clinic)]. https://collections.library.yale.edu/catalog/17145177.