1. Homological dimension of discrete group;Bieri;Queen Mary College Mathematics Notes,1981
2. Cohomology of Groups;Brown,1982
3. Homological Algebra;Cartan,1956
4. Groups which act freely on Rm X Sn−1;Connolly;Topology,1989
5. Poincaré duality groups of dimension two II;Eckmann;Comment. Math. Helv.,1983