TY  - JOUR
AU  - Ercan, Zafer
TI  - A generalisation of a theorem of Koldunov with an elementary proof
JO  - Czechoslovak Mathematical Journal
PY  - 1999
SP  - 187
EP  - 190
VL  - 49
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMJ_1999__49_1_a17/
LA  - en
ID  - CMJ_1999__49_1_a17
ER  -