Christofides, Demetres

• The Electronic Journal of Combinatorics Volume 18, Issue 1 (2011) - Papers
  The Guessing Number of Undirected Graphs
  Abstract  PDF
• The Electronic Journal of Combinatorics Volume 20, Issue 4 (2013) - Papers
  An Approximate Vertex-Isoperimetric Inequality for $r$-sets
  Abstract  PDF  official source