@article{02206527,
title = {Limit groups and groups acting freely on },
journal = {Geometry \& Topology},
volume = {8},
year = {2004},
pages = {1427-1470},
doi = {10.2140/gt.2004.8.1427},
zbl = {1114.20013},
language = {en},
url = {http://dml.mathdoc.fr/item/02206527}
}
Guirardel, Vincent. Limit groups and groups acting freely on . Geometry & Topology, Tome 8 (2004) pp. 1427-1470. doi : 10.2140/gt.2004.8.1427. http://gdmltest.u-ga.fr/item/02206527/