TY  - JOUR
AU  - Bednařík, Dušan
AU  - Pastor, Karel
TI  - A characterization of $C^{1,1}$ functions via lower directional derivatives
JO  - Mathematica Bohemica
PY  - 2009
SP  - 217
EP  - 221
VL  - 134
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.21136/MB.2009.140656/
DO  - 10.21136/MB.2009.140656
LA  - en
ID  - 10_21136_MB_2009_140656
ER  -