Gaya APA
Energy, M, O, M, A., Mines, D, G, O. (1986).
Ombillin II Coal Mine Development And Transportation Project Quarterly Repor .
Bandung:
Pusat Sumber Daya Geologi.
Gaya MLA
Energy, Ministry, Of, Mines, And., Mines, Directorate, General, Of.
"Ombillin II Coal Mine Development And Transportation Project Quarterly Repor".
Bandung:
Pusat Sumber Daya Geologi,
1986.
Batubara.