Bounds on the locating Roman dominating number in trees
Nader Jafari Rad, Hadi Rahbani · Discussiones Mathematicae Graph Theory · 2017
A Roman dominating function (or just RDF) on a graph G = (V, E) is a function f : V - {0, 1, 2} satisfying the condition that every vertex u for which f (u) = 0 is adjacent to at least one vertex v for which