Tirtadiwangsa F, Widagdo A. Estimasi Sumberdaya Batubara Menggunakan Metode Poligon Pada Seam D Daerah Lahat, Sumatera Selatan: Coal Resources Estimation Using the Polygon Method on Seam D Lahat Area, South Sumatera. JENERAL [Internet]. 2022 Jun. 26 [cited 2025 Aug. 10];3(1):11-7. Available from: https://jeneral.jurnal.unej.ac.id/index.php/JENERAL/article/view/30645