Gaya APA
Energy, M, O, M, A. (1986).
Ombilin II Coal Mine Development And Transportation Project .
Bandung:
Pusat Sumber Daya Geologi.
Gaya MLA
Energy, Ministry, Of, Mines, And.
"Ombilin II Coal Mine Development And Transportation Project".
Bandung:
Pusat Sumber Daya Geologi,
1986.
Batubara.