@article{JRAM_1970__242_151019,
     author = {Sophie Piccard},
     title = {Les groupes libres et les groupes quasi libres modulis {N.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {170--178},
     publisher = {mathdoc},
     volume = {242},
     year = {1970},
     zbl = {0196.04203},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1970__242_151019/}
}