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@article{TM_1953_40_a0, author = {A. A. Lyapunov}, title = {$R$-sets}, journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova}, pages = {3--68}, publisher = {mathdoc}, volume = {40}, year = {1953}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/TM_1953_40_a0/} }
A. A. Lyapunov. $R$-sets. Trudy Matematicheskogo Instituta imeni V.A. Steklova, $R$-sets, Tome 40 (1953), pp. 3-68. http://geodesic.mathdoc.fr/item/TM_1953_40_a0/