Purba, Y. W. ., P. K. Karo, and E. Ginting. “Analisis Batubara Jenis Antrasit Di PTBA Berdasarkan Kandungan Volatile Matter Dan Kalori”. Journal of Energy, Material, and Instrumentation Technology, vol. 1, no. 1, Mar. 2020, pp. 23-26, doi:10.23960/jemit.v1i1.9.