The Roman (k,k)-domatic number of a graph

A. P. Kazemi, S. M. Sheikholeslami, L. Volkmann

Let $k$ be a positive integer. A {\em Roman $k$-dominating function} on a graph $G$ is a labeling $f:V(G)⟶\{0,1,2\}$ such that every vertex with label 0 has at le…