MLA

Johnson, James Weldon, 1871-1938. from J. Rosamond Johnson. Box 40, folder 13. 1920-32. https://collections.library.yale.edu/catalog/16748019.

APA, 6th edition

Johnson, James Weldon, 1871-1938. (["Box 40, folder 13"])(1920-32)[from J. Rosamond Johnson]. https://collections.library.yale.edu/catalog/16748019.