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@article{DAN_1967_175_1_a9, author = {G. A. Utkin}, title = {Topological classification of non-singular fourth-order surfaces}, journal = {Doklady Akademii Nauk}, pages = {40--43}, publisher = {mathdoc}, volume = {175}, number = {1}, year = {1967}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1967_175_1_a9/} }
G. A. Utkin. Topological classification of non-singular fourth-order surfaces. Doklady Akademii Nauk, Tome 175 (1967) no. 1, pp. 40-43. http://geodesic.mathdoc.fr/item/DAN_1967_175_1_a9/