@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., Volume 14 (1970) no. 4, pp. 665-673. http://gdmltest.u-ga.fr/item/1256052960/