TY  - JOUR
AU  - Pyrih, Pavel
TI  - On the sense preserving mappings in the Helm topology in the plane
JO  - Serdica Mathematical Journal
PY  - 1999
SP  - 41
EP  - 46
VL  - 25
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SMJ2_1999_25_1_a4/
LA  - en
ID  - SMJ2_1999_25_1_a4
ER  -