Gaya APA

Project, W, C, O, C, S, C, E. (1989). Report on Semi Detailed Exploration of Central Sumatra Coal Exploration Project Appendix II Geophysical Log S.K. . Bandung: Pusat Sumber Daya Geologi.

Gaya MLA

Project, Working, Commitee, Of, Central, Sumatera, Coal, Eksploration. "Report on Semi Detailed Exploration of Central Sumatra Coal Exploration Project Appendix II Geophysical Log S.K.". Bandung: Pusat Sumber Daya Geologi, 1989. Batubara.