@article{1077469842, author = {Church, P. T. and Hemmingsen, E.}, title = {Light open maps on $n$ -manifolds. II}, journal = {Duke Math. J.}, volume = {28}, number = {1}, year = {1961}, pages = { 607-623}, language = {en}, url = {http://dml.mathdoc.fr/item/1077469842} }
Church, P. T.; Hemmingsen, E. Light open maps on $n$ -manifolds. II. Duke Math. J., Tome 28 (1961) no. 1, pp. 607-623. http://gdmltest.u-ga.fr/item/1077469842/