@article{PDML_1987___4B_9_0,
     author = {Berger, R.},
     title = {D\'eformations \'equivalentes avec des spectres diff\'erents},
     journal = {Publications du D\'epartement de math\'ematiques (Lyon)},
     pages = {9--24},
     publisher = {Universit\'e Claude Bernard - Lyon 1},
     number = {4B},
     year = {1987},
     language = {fr},
     url = {http://archive.numdam.org/item/PDML_1987___4B_9_0/}
}