@article{10_4171_ggd_323,
     author = {Nic Koban and Jon McCammond and John Meier},
     title = {The {BNS-invariant} for the pure braid groups},
     journal = {Groups, geometry, and dynamics},
     pages = {665--682},
     year = {2015},
     volume = {9},
     number = {3},
     doi = {10.4171/ggd/323},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/323/}
}