@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/}
}