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@article{DE_1976_12_2_a8, author = {S. K. Norkin}, title = {The problem of discrimination for the normal domain $N_4$ in the space $R^3$}, journal = {Differencialʹnye uravneni\^a}, pages = {263--271}, publisher = {mathdoc}, volume = {12}, number = {2}, year = {1976}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1976_12_2_a8/} }
S. K. Norkin. The problem of discrimination for the normal domain $N_4$ in the space $R^3$. Differencialʹnye uravneniâ, Tome 12 (1976) no. 2, pp. 263-271. http://geodesic.mathdoc.fr/item/DE_1976_12_2_a8/