@article{CMUC_1977__18_2_a8,
     author = {Rosick\'y, Ji\v{r}{\'\i}},
     title = {One obstruction for closedness},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {311--318},
     publisher = {mathdoc},
     volume = {18},
     number = {2},
     year = {1977},
     mrnumber = {0470025},
     zbl = {0359.18011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1977__18_2_a8/}
}