@article{JEP_2014__1__39_0,
     author = {M\'etivier, Guy},
     title = {$L^2$ well-posed {Cauchy} problems and symmetrizability of first order systems},
     journal = {Journal de l{\textquoteright}\'Ecole polytechnique - Math\'ematiques},
     pages = {39--70},
     publisher = {Ecole polytechnique},
     volume = {1},
     year = {2014},
     doi = {10.5802/jep.3},
     language = {en},
     url = {http://www.numdam.org/articles/10.5802/jep.3/}
}