TY  - JOUR
AU  - J. Ravetz
TI  - Derivate planes of continuous functions of two real variables
JO  - Fundamenta Mathematicae
PY  - 1957
SP  - 103
EP  - 114
VL  - 44
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/fm-44-1-103-114/
DO  - 10.4064/fm-44-1-103-114
LA  - en
ID  - 10_4064_fm_44_1_103_114
ER  -