@article{10_2140_agt_2011_11_587,
     author = {Williams, Kristopher},
     title = {Line arrangements and direct products of free groups},
     journal = {Algebraic and Geometric Topology},
     pages = {587--604},
     year = {2011},
     volume = {11},
     number = {1},
     doi = {10.2140/agt.2011.11.587},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2011.11.587/}
}