@article{1181073161,
author = {Cordes, C.M. and Foreman, D.L.},
title = {The square class invariant},
journal = {Rocky Mountain J. Math.},
volume = {20},
number = {4},
year = {1990},
pages = { 91-98},
language = {en},
url = {http://dml.mathdoc.fr/item/1181073161}
}
Cordes, C.M.; Foreman, D.L. The square class invariant. Rocky Mountain J. Math., Tome 20 (1990) no. 4, pp. 91-98. http://gdmltest.u-ga.fr/item/1181073161/