@article{CM_1935__2__463_0, author = {Erd\"os, P. and Szekeres, G.}, title = {A combinatorial problem in geometry}, journal = {Compositio Mathematica}, pages = {463--470}, publisher = {Johnson Reprint Corporation}, volume = {2}, year = {1935}, zbl = {0012.27010}, language = {en}, url = {http://archive.numdam.org/item/CM_1935__2__463_0/} }