6‐regular 4‐critical graph
A. V. Pyatkin · Journal of Graph Theory · 2002
Abstract P. Erdős conjectured in [2] that r‐regular 4‐critical graphs exist for every r ≥ 3 and noted that no such graphs are known for r ≥ 6. This article contains the first example of a 6‐regular 4‐critical graph. © 2002 Wiley Periodicals, Inc. J Graph Theory 41: 286–291, 2002