%0 Journal Article
%A P. Erdös
%A G. Purdy
%T Two Combinatorial Problems in the Plane.
%J Discrete & computational geometry
%D 1995
%P 441-444
%V 13
%N 3-4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DCG_1995__13_3-4_131372/
%F DCG_1995__13_3-4_131372