R. Padmavathi, S. Chandra Kumar. “Signed Total Domatic Number of Directed Circulant Graphs”. International Journal of Emerging Trends in Science and Technology, Vol. 4, no. 11, Nov. 2017, pp. 6361-5, http://igmpublication.org/ijetst.in/index.php/ijetst/article/view/1199.