Letter, signed "A.W.H."
MLA
Kilpatrick, Jack Frederick. Letter, Signed "A.W.H.". 1952. https://collections.library.yale.edu/catalog/15530904.
APA, 6th edition
Kilpatrick, J. F. (1952). Letter, signed "A.W.H.". https://collections.library.yale.edu/catalog/15530904.