@article{01928931, title = {Convergence groups from subgroups.}, journal = {Geometry \& Topology}, volume = {6}, year = {2002}, pages = {649-655}, doi = {10.2140/gt.2002.6.649}, zbl = {1021.20032}, language = {en}, url = {http://dml.mathdoc.fr/item/01928931} }
Swenson, Eric L. Convergence groups from subgroups.. Geometry & Topology, Tome 6 (2002) pp. 649-655. doi : 10.2140/gt.2002.6.649. http://gdmltest.u-ga.fr/item/01928931/