On a Generalization of Baer Theorem

L. A. Kurdachenko, J. Otal, I. YA. Subbotin

R. Baer has proved that if the factor-group G/ζ_{n}(G) of a group G by the member ζ_{n}(G) of its upper central series is finite (here n is a positive integer) then the member γ_{n…