@article{SMS_1969-1970__1__A4_0,
     author = {Nivat, Maurice},
     title = {Sur le noyau d'un homomorphisme du mono{\"\i}de libre dans un groupe libre},
     journal = {S\'eminaire Sch\"utzenberger},
     note = {talk:4},
     pages = {1--6},
     publisher = {Secr\'etariat math\'ematique},
     volume = {1},
     year = {1969-1970},
     mrnumber = {280625},
     zbl = {0215.56101},
     language = {fr},
     url = {http://www.numdam.org/item/SMS_1969-1970__1__A4_0/}
}