Valencia, C. J., J. M. . Calopez, R. . Carbos, M. . Anguluna, and C.-J. . Tamon. “Effectiveness of Voluntary Community Service to Maintain Cleanliness of Tullahan River in Nitang, Novaliches, Quezon City”. Ascendens Asia Singapore – Bestlink College of the Philippines Journal of Multidisciplinary Research, vol. 2, no. 1, Apr. 2020, https://ojs.aaresearchindex.com/index.php/aasgbcpjmra/article/view/1260.