1. [1] Harpe, Pierre Topics in Geometric Group Theory, Chicago Lectures in Mathematics, University of Chicago Press, 2000
2. [2] Geoghegan, Ross Topological Methods in Group Theory, Graduate Texts in Mathematics, 243, Springer, 2008
3. Free abelian cohomology of groups and ends of universal covers;Geoghegan, Ross;J. Pure Appl. Algebra,1985
4. Ascending HNN-extensions and properly -realisable groups;Lasheras, Francisco F.;Bull. Aust. Math. Soc.,2005
5. [5] Mardešić, Sibe; Segal, Jack Shape theory. The inverse system approach, North-Holland Mathematical Library, 26, North-Holland, 1982