@article{JRAM_1976__285_151764,
     author = {Kenneth S. Williams},
     title = {Note on a result of {Barrucand} and {Cohn.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {218--220},
     publisher = {mathdoc},
     volume = {285},
     year = {1976},
     zbl = {0325.10002},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1976__285_151764/}
}