1. M.P. Bellon, J.-M. Maillard and C.-M. Viallet, Infinite discrete symmetry group for the Yang-Baxter equations: spin models, preprint LPTHE 91-6 and Helsinki HU TFT 91-6.
2. Infinite discrete symmetry group for the Yang-Baxter equations. Vertex models
3. Generators and relations for discrete groups;Coxeter,1965
4. Nachr. Akad. Wiss. Göttingen II;Magnus;Math. Phys. Kl.,1975
5. Inverse functional relation on the Potts model