Anwar, H. ., I. . Khan, A. . Ahmed, and A. . Srivastava. “A REVIEW ON OPTIMAL PARAMETER SETTING FOR DIRECTIONAL RELAY IN MULTIMACHINE SYSTEM”. International Journal of Technical Innovation in Modern Engineering & Science, vol. 5, no. 2, Feb. 2019, pp. 342-6, https://ijtimes.com/index.php/ijtimes/article/view/2394.