In this paper, we have proved that if a contraction critical \(8\)-connected graph \(G\) has no vertices of degree \(8\), then for every vertex \(x\) of \(G\), either \(x\) is adjacent to a vertex of degree \(9\), or there are at least \(4\) vertices of degree \(9\) such that every one of them is at distance \(2\) from \(x\).
Citation
Yingqiu Yang. Vertices of Degree \(9\) in Contraction Critical \(8\)-Connected Graphs[J], Ars Combinatoria, Volume 131. 107-122. .