@article{10_2140_agt_2006_6_603,
     author = {Sakasai, Takuya},
     title = {Homology cylinders and the acyclic closure of a free group},
     journal = {Algebraic and Geometric Topology},
     pages = {603--631},
     year = {2006},
     volume = {6},
     number = {2},
     doi = {10.2140/agt.2006.6.603},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2006.6.603/}
}