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@article{PIM_1998_N_S_63_77_a6, author = {I. Barza and D. Ghisa and Stere Ianus}, title = {Some {Remarks} on the {Nonorientable} {Surfaces}}, journal = {Publications de l'Institut Math\'ematique}, pages = {47 }, publisher = {mathdoc}, volume = {_N_S_63}, number = {77}, year = {1998}, zbl = {1002.53007}, language = {en}, url = {http://geodesic.mathdoc.fr/item/PIM_1998_N_S_63_77_a6/} }
I. Barza; D. Ghisa; Stere Ianus. Some Remarks on the Nonorientable Surfaces. Publications de l'Institut Mathématique, _N_S_63 (1998) no. 77, p. 47 . http://geodesic.mathdoc.fr/item/PIM_1998_N_S_63_77_a6/