@article{GT_2004_8_3_a12,
     author = {Guirardel, Vincent},
     title = {Limit groups and groups acting freely on {\ensuremath{\mathbb{R}}n{\textendash}trees}},
     journal = {Geometry & topology},
     pages = {1427--1470},
     publisher = {mathdoc},
     volume = {8},
     number = {3},
     year = {2004},
     doi = {10.2140/gt.2004.8.1427},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/gt.2004.8.1427/}
}