@article{1270473562,
author = {AMANO, Kazuo},
title = {A Necessary Condition for Hypoellipticity of Degenerate Elliptic-Parabolic Operators},
journal = {Tokyo J. of Math.},
volume = {02},
number = {2},
year = {1979},
pages = { 111-120},
language = {en},
url = {http://dml.mathdoc.fr/item/1270473562}
}
AMANO, Kazuo. A Necessary Condition for Hypoellipticity of Degenerate Elliptic-Parabolic Operators. Tokyo J. of Math., Tome 02 (1979) no. 2, pp. 111-120. http://gdmltest.u-ga.fr/item/1270473562/