“…It is well-known that given a graph G and an integer k, the problem of deciding if there is a PD-set in G of cardinality at most k is NP-complete [17], even for bipartite graphs [24], split graphs [24] or planar graphs [36]. Thus, most of the papers, as for example [1,5,8,22,24,25,28,32,36] and the references therein, focus on studying the complexity of computing the paired domination number in several restricted graph classes.…”