@article{1250776059,
author = {Kasahara, Koji and Yamaguti, Masaya},
title = {Strongly hyperbolic systems of linear partial differential equations with constant coefficients},
journal = {Mem. College Sci. Univ. Kyoto Ser. A Math.},
volume = {33},
number = {2},
year = {1960},
pages = { 1-23},
language = {en},
url = {http://dml.mathdoc.fr/item/1250776059}
}
Kasahara, Koji; Yamaguti, Masaya. Strongly hyperbolic systems of linear partial differential equations with constant coefficients. Mem. College Sci. Univ. Kyoto Ser. A Math., Tome 33 (1960) no. 2, pp. 1-23. http://gdmltest.u-ga.fr/item/1250776059/