@article{CMUC_1977__18_4_a7,
     author = {Svoboda, Karel},
     title = {Remark to the characterization of the sphere in $E^4$},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {715--722},
     publisher = {mathdoc},
     volume = {18},
     number = {4},
     year = {1977},
     mrnumber = {0493901},
     zbl = {0368.53039},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1977__18_4_a7/}
}