G. R. Roshini, S. B. Chandrakala, R. Indira, and B. Sooryanarayana. “Non-Neighbor Reduced Randic and Sum-Connectivity Index”. International Journal of Mathematics And Its Applications, vol. 7, no. 3, Sept. 2019, pp. 127-33, http://ijmaa.in/index.php/ijmaa/article/view/238.