On the existence of countable universal graphs
Zolt�n F�redi, P�ter Komj�th · Journal of Graph Theory · 1997
Let Forb(G) denote the class of graphs with countable vertex sets which do not contain G as a subgraph. If G is finite, 2-connected, but not complete, then Forb(G) has no element which contains every other element of Forb(G) as a subgraph, i.e., this class contains no universal graph. © 1997 John Wiley & Sons, Inc. J Graph Theory 25: 53–58, 1997