Nababan, S. A., Pulung Sumantri, Yushar Tanjung, and A. N. . Hasudungan. “Student’s Coaching During the Covid-19 Pandemic in the SMAN 1 Rupat: National Science Competition in 2021”. East Asian Journal of Multidisciplinary Research, vol. 1, no. 2, Apr. 2022, pp. 175-84, https://journal.formosapublisher.org/index.php/eajmr/article/view/86.