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@article{DAN_1975_224_2_a0, author = {V. I. Amstislavskii}, title = {On recursive characterizations of sets obtainable by means of $R^c$-operations}, journal = {Doklady Akademii Nauk}, pages = {257--260}, publisher = {mathdoc}, volume = {224}, number = {2}, year = {1975}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1975_224_2_a0/} }
V. I. Amstislavskii. On recursive characterizations of sets obtainable by means of $R^c$-operations. Doklady Akademii Nauk, Tome 224 (1975) no. 2, pp. 257-260. http://geodesic.mathdoc.fr/item/DAN_1975_224_2_a0/