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@article{DE_1972_8_11_a15, author = {S. M. Ponomarev}, title = {Semigroups of the classes $A^{n,\alpha}$ and the abstract {Cauchy} problem}, journal = {Differencialʹnye uravneni\^a}, pages = {2038--2047}, publisher = {mathdoc}, volume = {8}, number = {11}, year = {1972}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1972_8_11_a15/} }
S. M. Ponomarev. Semigroups of the classes $A^{n,\alpha}$ and the abstract Cauchy problem. Differencialʹnye uravneniâ, Tome 8 (1972) no. 11, pp. 2038-2047. http://geodesic.mathdoc.fr/item/DE_1972_8_11_a15/