Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1977_13_2_a5, author = {A. M. Abdrakhmanov}, title = {Elliptic systems that are degenerate at a point}, journal = {Differencialʹnye uravneni\^a}, pages = {276--284}, publisher = {mathdoc}, volume = {13}, number = {2}, year = {1977}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1977_13_2_a5/} }
A. M. Abdrakhmanov. Elliptic systems that are degenerate at a point. Differencialʹnye uravneniâ, Tome 13 (1977) no. 2, pp. 276-284. http://geodesic.mathdoc.fr/item/DE_1977_13_2_a5/