00390nam a2200121 a 450000500170000002000180001708200150003510000160005024500810006626000470014730000240019449000500021820251203111001.0  a9780521719773  a512.2bMEI  aMeier, John  aGroups, graphs and treesban introduction to the geometry of infinite groups  aNew yorkbCambridge university pressc2008  axi,231p.c22cm.cPB  aLondon mathematical society, student texts 73