Lukman, -, H. Hidayat, Luki Subehi, Rahmi Dina, Novi Mayasari, Irma Melati, and Yuli Sudriani. “Loads of Pollution to Lake Toba and Their Impacts”. International Journal on Advanced Science, Engineering and Information Technology 11, no. 3 (June 10, 2021): 930–936. Accessed June 3, 2024. http://ijaseit.insightsociety.org/index.php/ijaseit/article/view/12733.