@article{1256052960, author = {Crowell, R. H.}, title = {$H\_{2}$ of subgroups of knot groups}, journal = {Illinois J. Math.}, volume = {14}, number = {4}, year = {1970}, pages = { 665-673}, language = {en}, url = {http://dml.mathdoc.fr/item/1256052960} }
Crowell, R. H. $H_{2}$ of subgroups of knot groups. Illinois J. Math., Tome 14 (1970) no. 4, pp. 665-673. http://gdmltest.u-ga.fr/item/1256052960/