@article{1077475902,
author = {Whyburn, G. T.},
title = {Open and closed mappings},
journal = {Duke Math. J.},
volume = {17},
number = {1},
year = {1950},
pages = { 69-74},
language = {en},
url = {http://dml.mathdoc.fr/item/1077475902}
}
Whyburn, G. T. Open and closed mappings. Duke Math. J., Tome 17 (1950) no. 1, pp. 69-74. http://gdmltest.u-ga.fr/item/1077475902/