Gaya APA
(tidak ada) Presentation On Central Sumatra Joint Coal Exploration Project. (1991).
Bandung:
Pusat Sumber Daya Geologi.
Gaya MLA
(tidak ada) Presentation On Central Sumatra Joint Coal Exploration Project.
.
Bandung:
Pusat Sumber Daya Geologi,
1991.
Logam.