Voir la notice de l'article provenant de la source Math-Net.Ru
@article{MAT_1963_7_1_a3, author = {L. H\"ormander}, title = {Hypoelliptic differential operators}, journal = {Matematika}, pages = {66--78}, publisher = {mathdoc}, volume = {7}, number = {1}, year = {1963}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MAT_1963_7_1_a3/} }
L. Hörmander. Hypoelliptic differential operators. Matematika, Tome 7 (1963) no. 1, pp. 66-78. http://geodesic.mathdoc.fr/item/MAT_1963_7_1_a3/