Gaya APA
Energy, M, O, M, A. (1986).
Ombilin II Coal Mine Development And Transportation Project, Conceptual Report Volume VII Project Optimization .
Bandung:
Direktorat Sumber Daya Mineral.
Gaya MLA
Energy, Ministry, Of, Mines, And.
"Ombilin II Coal Mine Development And Transportation Project, Conceptual Report Volume VII Project Optimization".
Bandung:
Direktorat Sumber Daya Mineral,
1986.
Batubara.