1. Z. Y.Duan, Noetherian modules over hyperfinite groups. Ph.D. Thesis, University of Glasgow 1991.
2. Z. Y. Duan, The structure of noetherian modules over hyperfinite groups. Math. Proc. Cambridge Philos. Soc.112, 21?28 (1992).
3. D. J. S.Robinson, Finiteness conditions and generalized soluble groups, I. Ergebnisse der Mathematik und ihrer Grenzgebiete, Band 63. Berlin-Heidelberg-New York 1972.
4. D. I. Zaitsev, Splitting of extensions of abelian groups (Russian). Akad. Nauk Ukrain. SSR, Inst. Mat, Kiev, 21?31 (1986).