19 citations · 35 across the 2 of their papers we have counts for
2 papers
math.CO2013★ 19 cited
Planar 4-critical graphs with four triangles
Oleg V. Borodin, Zdeněk Dvořák, Alexandr V. Kostochka +2
By the Grunbaum-Aksenov Theorem (extending Grotzsch's Theorem) every planar graph with at most three triangles is 3-colorable. However, there are infinitely many planar 4-critical…
math.CO2012★ 16 cited
Short proofs of coloring theorems on planar graphs
Oleg V. Borodin, Alexandr V. Kostochka, Bernard Lidický +1
A recent lower bound on the number of edges in a k-critical n-vertex graph by Kostochka and Yancey yields a half-page proof of the celebrated Grötzsch Theorem that every planar tri…