Gaya APA
Mines, D, G, O. (1983).
Mara Tiga Coal Exploration Project Inception Report .
Bandung:
DR.otto gold consulting engineers.
Gaya MLA
Mines, Directorate, General, Of.
"Mara Tiga Coal Exploration Project Inception Report".
Bandung:
DR.otto gold consulting engineers,
1983.
Batubara.