On the critical graph conjecture
Hian Poh Yap · Journal of Graph Theory · 1980
Abstract Gol'dberg has recently constructed an infinite family of 3‐critical graphs of even order. We now prove that if there exists a p(≥4)‐critical graph K of odd order such that K has a vertex u of valency 2 and another vertex v ≠ u of valency ≤(p + 2)/2, then there exists a p‐critical graph of even order.