Richard (Dick) Crowell was emeritus professor of mathematics at Dartmouth College. He is best known for his book on knot theory written with Ralph Fox, but also wrote on the derived module of a homomorphism, related to the Fox derivatives.
R. H. Crowell and R. H. Fox, 1977, Introduction to Knot Theory, number 57 in Graduate Texts, Springer.
R. H. Crowell, The derived module of a homomorphism, Advances in Math., 5, (1971), 210–238.