Mathew Varkey T.K , Mini.S.Thomas. “Cubic Harmonious Labeling Of Certain Star and Bistar Graphs”. International Journal of Emerging Trends in Science and Technology, Vol. 4, no. 11, Nov. 2017, pp. 6301-5, https://igmpublication.org/ijetst.in/index.php/ijetst/article/view/1190.