TY  - JOUR
AU  - H. H. Pu
AU  - H. W. Pu
TI  - An approximative generalization of Zahorski's theorem on derivative
JO  - Colloquium Mathematicum
PY  - 1978
SP  - 81
EP  - 86
VL  - 39
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/cm-39-1-81-86/
DO  - 10.4064/cm-39-1-81-86
LA  - en
ID  - 10_4064_cm_39_1_81_86
ER  -