1. Cohomology of Groups;Brown,1982
2. An enumeration of knots and links, and some of their algebraic properties;Conway,1970
3. Introduction to Knot Theory;Crowell,1963
4. A new polynomial invariant of knots and links;Freyd;Bull. A.M.S.,1985
5. A polynomial invariant for knots via von Neumann algebras;Jones;Bull. A.M.S.,1985