@article{105814, author = {Karel Svoboda}, title = {Remark to the characterization of the sphere in $E^4$}, journal = {Commentationes Mathematicae Universitatis Carolinae}, volume = {018}, year = {1977}, pages = {715-722}, zbl = {0368.53039}, mrnumber = {0493901}, language = {en}, url = {http://dml.mathdoc.fr/item/105814} }
Svoboda, Karel. Remark to the characterization of the sphere in $E^4$. Commentationes Mathematicae Universitatis Carolinae, Tome 018 (1977) pp. 715-722. http://gdmltest.u-ga.fr/item/105814/
Contributions to the global differential geometry on surfaces, Rozpravy ČSAV, 87, 1, 1977, 1-94. (1977) | MR 0467608
Some global characterizations of the sphere in $E^4$, Čas. pгo pěst. matem. - to appear. | MR 0512236