Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1970_6_5_a11, author = {N. T. Pham}, title = {Boundary value problems for natural differential operators on manifolds}, journal = {Differencialʹnye uravneni\^a}, pages = {877--888}, publisher = {mathdoc}, volume = {6}, number = {5}, year = {1970}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1970_6_5_a11/} }
N. T. Pham. Boundary value problems for natural differential operators on manifolds. Differencialʹnye uravneniâ, Tome 6 (1970) no. 5, pp. 877-888. http://geodesic.mathdoc.fr/item/DE_1970_6_5_a11/