@article{10_2140_agt_2001_1_243,
     author = {Levine, Jerome},
     title = {Homology cylinders: an enlargement of the mapping class group},
     journal = {Algebraic and Geometric Topology},
     pages = {243--270},
     year = {2001},
     volume = {1},
     number = {1},
     doi = {10.2140/agt.2001.1.243},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2001.1.243/}
}