@article{RSMUP_1977__57__267_0,
     author = {Berechet, Oprea},
     title = {Le probl\`eme de {Cauchy} pour op\'erateurs partiellement semi-elliptiques},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {267--284},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {57},
     year = {1977},
     mrnumber = {526195},
     zbl = {0404.35025},
     language = {fr},
     url = {http://archive.numdam.org/item/RSMUP_1977__57__267_0/}
}