@article{1153494554, author = {Ebert, Marcelo Rempel}, title = {On the Cauchy problem for $2\times 2$ weakly hyperbolic systems}, journal = {Osaka J. Math.}, volume = {42}, number = {1}, year = {2005}, pages = { 831-860}, language = {en}, url = {http://dml.mathdoc.fr/item/1153494554} }
Ebert, Marcelo Rempel. On the Cauchy problem for $2\times 2$ weakly hyperbolic systems. Osaka J. Math., Tome 42 (2005) no. 1, pp. 831-860. http://gdmltest.u-ga.fr/item/1153494554/