@article{IM_1985__81_143256,
     author = {A.J., Long, D.D. Casson},
     title = {Algorithmic compression of surface automorphisms.},
     journal = {Inventiones mathematicae},
     pages = {295--304},
     publisher = {mathdoc},
     volume = {81},
     year = {1985},
     zbl = {0589.57008},
     url = {http://geodesic.mathdoc.fr/item/IM_1985__81_143256/}
}