Gaya APA
Prijono, A. (1993).
Seminar On Effective Utilization Of Coal In Indonesia .
Bandung:
Directorate Of Mineral Resources.
Gaya MLA
Prijono, Achmad.
"Seminar On Effective Utilization Of Coal In Indonesia".
Bandung:
Directorate Of Mineral Resources,
1993.
Batubara.