@article{PDML_1987___1B_163_0,
     author = {Berger, R.},
     title = {D\'eformations et lois de groupes formels},
     journal = {Publications du D\'epartement de math\'ematiques (Lyon)},
     pages = {163--173},
     publisher = {Universit\'e Claude Bernard - Lyon 1},
     number = {1B},
     year = {1987},
     mrnumber = {907072},
     language = {fr},
     url = {http://www.numdam.org/item/PDML_1987___1B_163_0/}
}