@article{10_2307_121043,
     author = {Mladen Bestvina and Mark Feighn and Michael Handel},
     title = {The {Tits} alternative for {\(\text{Out}(F_n)\).} {I:} {Dynamics} of exponentially-growing automorphisms},
     journal = {Annals of mathematics},
     year = {2000},
     volume = {151},
     number = {2},
     doi = {10.2307/121043},
     zbl = {0984.20025},
     url = {http://geodesic.mathdoc.fr/articles/10.2307/121043/}
}