Piyadasa, R. U. K., and M. D. C. Fernando. “Groundwater Pollution Vulnerability by Drastic Method in Ja-Ela Divisional Secretorial Division, Sri Lanka”. European Journal of Science, Innovation and Technology, Vol. 1, no. 5, Nov. 2021, pp. 17-22, https://ejsit-journal.com/index.php/ejsit/article/view/33.