@article{1250521017,
author = {\=Okaji, Takashi},
title = {On the lowest index for semi-elliptic operators to be Gevrey hypoelliptic},
journal = {J. Math. Kyoto Univ.},
volume = {25},
number = {4},
year = {1985},
pages = { 693-701},
language = {en},
url = {http://dml.mathdoc.fr/item/1250521017}
}
Ōkaji, Takashi. On the lowest index for semi-elliptic operators to be Gevrey hypoelliptic. J. Math. Kyoto Univ., Tome 25 (1985) no. 4, pp. 693-701. http://gdmltest.u-ga.fr/item/1250521017/