Bounds on the Distance Two-Domination Number of a Graph. - N. Sridharan; V. S. A. Subramanian; M. D. Elias (Graphs Comb., 2002)

Characterization of Graphs G for which I. - N. Sridharan; M. D. Elias; V. S. A. Subramanian (Electron. Notes Discret. Math., 2003)