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@article{IVM_1971_12_a6, author = {P. Zenf}, title = {A~certain theorem on groups with an invariant mean}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {63--65}, publisher = {mathdoc}, number = {12}, year = {1971}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1971_12_a6/} }
P. Zenf. A~certain theorem on groups with an invariant mean. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 12 (1971), pp. 63-65. http://geodesic.mathdoc.fr/item/IVM_1971_12_a6/