Chvátal, Vašek

• The Electronic Journal of Combinatorics Volume 17 (2010) - Notes
  Another Abstraction of the Erdős-Szekeres Happy End Theorem
  Abstract  PDF
• The Electronic Journal of Combinatorics Volume 22, Issue 1 (2015) - Papers
  A De Bruijn–Erdős Theorem for Chordal Graphs
  Abstract  PDF  revised version  revised version/PDF  Official source