@article{AM_2000_151_2_a3,
     author = {Mladen Bestvina and Mark Feighn and Michael Handel},
     title = {The {Tits} alternative for {Out}$(F_n)$. {I:} {Dynamics} of exponentially-growing automorphisms},
     journal = {Annals of mathematics},
     publisher = {mathdoc},
     volume = {151},
     number = {2},
     year = {2000},
     url = {http://geodesic.mathdoc.fr/item/AM_2000_151_2_a3/}
}