MLA

Johnson, James Weldon, 1871-1938. from James Weldon Johnson. Box 41, folder 23. 1912 Sep-Dec. https://collections.library.yale.edu/catalog/17235685.

APA, 6th edition

Johnson, James Weldon, 1871-1938. (["Box 41, folder 23"])(1912 Sep-Dec)[from James Weldon Johnson]. https://collections.library.yale.edu/catalog/17235685.