@article{CMH_1950__24_139012,
     author = {Erwin Bareiss},
     title = {Hyperbolische {Systeme} von partiellen {Differentialgleichungen} mit konstanten {Koeffizienten.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {291--331},
     publisher = {mathdoc},
     volume = {24},
     year = {1950},
     zbl = {0040.34503},
     url = {http://geodesic.mathdoc.fr/item/CMH_1950__24_139012/}
}