00430nam a2200133Ia 4500008004100000020001500041082001700056100002000073245006600093260003800159300002800197440004300225700002800268260908b        |||||||| |||| 00| 0 eng d  a3110175266  a516bF331.DG  aFenchel, Werner  aDiscontinuous groups of isometries in the hyperbolic planeb/  aBerlin:bWalter de Gruyter,c2003  axxi, 364p. Bibl. Index.  aDe Gruyter studies in Mathematics ; 29  aNielsen, Jakobeauthor.