@article{CMH_1980__55_139832,
     author = {Roger Alperin},
     title = {Homology of {SL2(Z[...]).}},
     journal = {Commentarii mathematici Helvetici},
     pages = {364--377},
     year = {1980},
     volume = {55},
     url = {http://geodesic.mathdoc.fr/item/CMH_1980__55_139832/}
}