@article{CMUC_1978__19_4_a0,
     author = {Svoboda, Karel},
     title = {Remark on surfaces in $E^4$ satisfying certain relations between covariant derivatives of the mean and {Gauss} curvatures},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {619--626},
     publisher = {mathdoc},
     volume = {19},
     number = {4},
     year = {1978},
     mrnumber = {518175},
     zbl = {0397.53044},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1978__19_4_a0/}
}