The hull number of an oriented graph
Gary Chartrand, John Frederick Fink, Ping Zhang · International Journal of Mathematics and Mathematical Sciences · 2003
We present characterizations of connected graphs G of order n ≥ 2 for which h+(G) = n. It is shown that for every two integers n and m with , there exists a connected graph G of order n and size m such that for each integer k with 2 ≤ k ≤ n, there exists an orientation of G with hull number G.