@article{10_2307_121031,
     author = {S. Boyer and X. Zhang},
     title = {On {Culler-Shalen} seminorms and {Dehn} filling},
     journal = {Annals of mathematics},
     year = {1998},
     volume = {148},
     number = {3},
     doi = {10.2307/121031},
     zbl = {1007.57016},
     url = {http://geodesic.mathdoc.fr/articles/10.2307/121031/}
}