Elwiza, A., and M. Khair. “Analisa Pengaruh Kadar Abu (Ash Content) Terhadap Nilai Kalor Batubara Dengan Metode BS/ISO Di PT Bukit Asam Tbk”. MASALIQ, Vol. 5, no. 5, Sept. 2025, pp. 2526-40, doi:10.58578/masaliq.v5i5.7379.