TY  - JOUR
AU  - P. Erdös
AU  - G. Purdy
TI  - Two Combinatorial Problems in the Plane.
JO  - Discrete & computational geometry
PY  - 1995
SP  - 441
EP  - 444
VL  - 13
IS  - 3-4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DCG_1995__13_3-4_131372/
ID  - DCG_1995__13_3-4_131372
ER  -