Gaya APA
Lloyd, A, R. (1981).
REPORT ON SECOND COAL RECONNAISSANCE PERMIT OVER WESI SUMATRA,INDONESIA. .
Bandung:
Direktorat Sumber Daya Mineral.
Gaya MLA
Lloyd, A, R.
"REPORT ON SECOND COAL RECONNAISSANCE PERMIT OVER WESI SUMATRA,INDONESIA.".
Bandung:
Direktorat Sumber Daya Mineral,
1981.
Batubara.