ERWIN HARAHAP, D.; ASTUTI KUSWARDANI, R. .; HS SIREGAR, T. .; DARWIS, M. . Nira Production In Terms Of Slope Level In South Tapanuli District. International Journal of Science and Environment (IJSE), [S. l.], v. 4, n. 4, p. 112–116, 2024. DOI: 10.51601/ijse.v4i4.115. Disponível em: https://www.ijsenet.com/index.php/IJSE/article/view/115. Acesso em: 20 may. 2025.