Gaya APA

Proposal, G, A, T. (1992). Republic of Indonesia Ministry of Mines and Energy Directorate General of Mines Directorate of Coal . Bandung: Pusat Sumber Daya Geologi.

Gaya MLA

Proposal, General, And, Technical. "Republic of Indonesia Ministry of Mines and Energy Directorate General of Mines Directorate of Coal". Bandung: Pusat Sumber Daya Geologi, 1992. Batubara.