Richard H. Crowell et Ralph H. Fox, Introduction to Knot Theory, Springer-Verlag, coll.«Graduate Texts in Mathematics» (no57), (ISBN0-387-90272-4) — Réimpression de l’édition originale de 1963.
Ralph H. Fox, «A quick trip through knot theory», dans M. K. Fort (éditeur), Topology of 3-Manifolds and Related Topics', Prentice-Hall, (MR0140099), p.120–167.
Ralph H. Fox, «A characterization of absolute neighborhood retracts», Bulletin of the American Mathematical Society, vol.48, no4, , p.271–275 (DOI10.1090/s0002-9904-1942-07652-x, MR0006508)
Ralph H. Fox, «On Homotopy and Extension of Mappings», Proceedings of the National Academy of Sciences of the United States of America, vol.26, no1, , p.26–28 (PMID16577957, PMCID1078000, DOI10.1073/pnas.26.1.26)
↑Ralph H. Fox, Proceedings of the International Congress of Mathematicians, Cambridge, Massachusetts, U.S.A., August 30–September 6, 1950, vol.2, (lire en ligne), p.453–458.
Jozef H. Przytycki, «Notes to the early history of the Knot Theory in Japan», Annals of the Institute for Comparative Studies of Culture, TWCU, Vol. 63, 2002, 61-86, vol.63, , p.61-86 (arXivmath/0108072, lire en ligne, consulté le )