Gaya APA
Report On Exploration Of Central Sumatra Coal Exploration Project, Appendix VI Geotechnical Analysisi. (1990).
Bandung:
Butterworths.
Gaya MLA
Report On Exploration Of Central Sumatra Coal Exploration Project, Appendix VI Geotechnical Analysisi.
.
Bandung:
Butterworths,
1990.
Batubara.