Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1981_17_5_a15, author = {A. M. Abdrakhmanov}, title = {On a first-order system which is degenerating at a point}, journal = {Differencialʹnye uravneni\^a}, pages = {913}, publisher = {mathdoc}, volume = {17}, number = {5}, year = {1981}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1981_17_5_a15/} }
A. M. Abdrakhmanov. On a first-order system which is degenerating at a point. Differencialʹnye uravneniâ, Tome 17 (1981) no. 5. http://geodesic.mathdoc.fr/item/DE_1981_17_5_a15/