TY - JOUR AU - Svoboda, Karel TI - Characterizations of the sphere in $E^4$ by means of the pseudoparallel mean curvature vector field JO - Časopis pro pěstování matematiky PY - 1980 SP - 266 EP - 277 VL - 105 IS - 3 PB - mathdoc UR - http://geodesic.mathdoc.fr/articles/10.21136/CPM.1980.118069/ DO - 10.21136/CPM.1980.118069 LA - en ID - 10_21136_CPM_1980_118069 ER -