Gaya APA
Duisburg, D, N, G, M, B, H. (1957).
Briqueting Test With Clay Ore And Coal From SE Kalimantan .
Bandung:
Pusat Sumber Daya Geologi.
Gaya MLA
Duisburg, Demag-Humboldt, Niederschachtofen, G, M, B, H.
"Briqueting Test With Clay Ore And Coal From SE Kalimantan".
Bandung:
Pusat Sumber Daya Geologi,
1957.
Batubara.