@article{1195519402, author = {Tsutsumi, Akira}, title = {A remark on a sufficient condition for hypoellipticity}, journal = {Proc. Japan Acad.}, volume = {49}, number = {9}, year = {1973}, pages = { 187-190}, language = {en}, url = {http://dml.mathdoc.fr/item/1195519402} }
Tsutsumi, Akira. A remark on a sufficient condition for hypoellipticity. Proc. Japan Acad., Tome 49 (1973) no. 9, pp. 187-190. http://gdmltest.u-ga.fr/item/1195519402/