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@article{DAN_1957_117_2_a6, author = {I. D. Stupina}, title = {Properties of some $\delta s$-operations}, journal = {Doklady Akademii Nauk}, pages = {188--190}, publisher = {mathdoc}, volume = {117}, number = {2}, year = {1957}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1957_117_2_a6/} }
I. D. Stupina. Properties of some $\delta s$-operations. Doklady Akademii Nauk, Tome 117 (1957) no. 2, pp. 188-190. http://geodesic.mathdoc.fr/item/DAN_1957_117_2_a6/