@article{ASNSP_1994_4_21_1_97_0,
     author = {Nishitani, Tatsuo},
     title = {Symmetrization of hyperbolic systems with real constant coefficients},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {97--130},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 21},
     number = {1},
     year = {1994},
     mrnumber = {1276764},
     zbl = {0866.35063},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1994_4_21_1_97_0/}
}