Keywords: Markström-Graph.png Markström-Graph svg Markström's 24-vertex cubic planar graph with no 4- or 8-cycles found in a computer search for counterexamples to the ErdÅ‘s “Gyárfás conjecture Author en User David Eppstein The author released it in the public domain David Eppstein Files by User David Eppstein from en wikipedia Paul ErdÅ‘s undirected planar graphs |