@article{GT_2009_13_3_a9,
     author = {Feighn, Mark and Handel, Michael},
     title = {Abelian subgroups of {Out(Fn)}},
     journal = {Geometry & topology},
     pages = {1657--1727},
     publisher = {mathdoc},
     volume = {13},
     number = {3},
     year = {2009},
     doi = {10.2140/gt.2009.13.1657},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/gt.2009.13.1657/}
}