“…Various graph theoretic properties and parameters of graphs having disjoint dominating sets are studied in [1,8,9,10,14,20,21]. Characterizations of graphs with disjoint dominating and total dominating sets are given in [11,12,13,16,17,19,25], while in [2,4,5,6,18] graphs which have the property that their vertex set can be partitioned into two disjoint total dominating sets are studied. Conditions which guarantee the existence of a dominating set whose complement contains a 2-dominating set, a paired-dominating set or an independent dominating set are presented in [7,12,15,19,20,22,26].…”