TY  - JOUR
AU  - János Aczél
AU  - Marek Kuczma
TI  - On two mean value properties and functional equations associated with them.
JO  - Aequationes mathematicae
PY  - 1989
SP  - 216
EP  - 235
VL  - 38
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/AM2_1989__38_1_137329/
ID  - AM2_1989__38_1_137329
ER  -