MLA

Johnson, James Weldon, 1871-1938. Anderson, Charles W.. Box 2, folder 22. 1915-26, undated. https://collections.library.yale.edu/catalog/16747973.

APA, 6th edition

Johnson, James Weldon, 1871-1938. (["Box 2, folder 22"])(1915-26, undated)[Anderson, Charles W.]. https://collections.library.yale.edu/catalog/16747973.