1. M. Rasetti, Ising Model on Finitely Presented Groups, in “Group Theoretical Methods in Physics”, M. Serdaroglu and E. Inönü eds.; Springer Verlag, Lecture Notes in Physics180; Berlin, 1983 plus references therein and in
2. G. Jacucci and M. Rasetti, J. Phys. Chem.91, 4970 (1987)
3. L. Alvarez-Gaumé, G. Moore and C. Vafa, Commun. Math. Phys.106, 1 (1986)
4. A.M. Polyakov, Phys. Lett.103 B, 207 and 211 (1981)
5. J.S. Birman,Braids, Links and Mapping Class Groups; Annals of Mathematics Studies82; Priceton University Press; Priceton, 1974