Gaya APA
Ch.A.F.Macke, . (1921).
Results Of The Geological Mining Investigation In Southeast Borneo .
Bandung:
Pusat Sumber Daya Geologi.
Gaya MLA
Ch.A.F.Macke, .
"Results Of The Geological Mining Investigation In Southeast Borneo".
Bandung:
Pusat Sumber Daya Geologi,
1921.
Batubara.