1. Zur Isotopie zweidimensionaler Flächen in R4;Artin;Abh. Math. Sem. Univ. Hamburg,1926
2. Cubes with knotted holes;Bing;Trans. Am. math. Soc.,1971
3. Eine Kennzeichnung der Torusknoten;Burde;Math. Ann.,1966
4. Superspinning and knot complements;Cappell,1970
5. Generators and Relations for Discrete Groups;Coxeter,1957