Gaya APA

Project, W, C, O, C, S, C, E. (1989). Report on Exploration of Central Sumatera Coal Exploration Project Vol.IB : Maps and Sections . Bandung: Pusat Sumber Daya Geologi.

Gaya MLA

Project, Working, Commitee, Of, Central, Sumatera, Coal, Eksploration. "Report on Exploration of Central Sumatera Coal Exploration Project Vol.IB : Maps and Sections". Bandung: Pusat Sumber Daya Geologi, 1989. Batubara.