Allen Hatcher, Algebraic Topology, Cambridge U. Peter May, A Concise Course in Algebraic Topology, U. Louis Kauffman, On Knots, Princeton U. Louis Kauffman, Knots and Physics, World Scientific, Singapore, 1991. Dale Rolfsen, Knots and Links, Publish or Perish, Berkeley, 1976. 4 characters), Academic Press, 1980. Academic Press, New York, 1979.