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@article{IVM_1985_11_a1, author = {I. S. Ashmanov and A. Yu. Ol'shanskiǐ}, title = {Abelian and central extensions of aspherical groups}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {48--60}, publisher = {mathdoc}, number = {11}, year = {1985}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1985_11_a1/} }
I. S. Ashmanov; A. Yu. Ol'shanskiǐ. Abelian and central extensions of aspherical groups. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 11 (1985), pp. 48-60. http://geodesic.mathdoc.fr/item/IVM_1985_11_a1/