@article{1250521976,
author = {Urabe, Jiichiroh},
title = {On Hamada's theorem for a certain of the operators with double characteristics},
journal = {J. Math. Kyoto Univ.},
volume = {21},
number = {4},
year = {1981},
pages = { 517-535},
language = {en},
url = {http://dml.mathdoc.fr/item/1250521976}
}
Urabe, Jiichiroh. On Hamada’s theorem for a certain of the operators with double characteristics. J. Math. Kyoto Univ., Tome 21 (1981) no. 4, pp. 517-535. http://gdmltest.u-ga.fr/item/1250521976/