1. Thue systems as rewriting systems;Book;J. Symbolic Comput.,1987
2. Universal Algebra;Cohn,1965
3. Free distributive groupoids;Dehornoy;J. Pure Appl. Algebra,1989
4. Sur la structure des gerbes libres;Dehornoy;Comptes-rendus de l' Acad. des Sciences de Paris,1989
5. P. Dehornoy, A structural monoids associated to equational varieties, Proc. Amer. Math. Soc., à paraître.