Gaya APA
E., J, U, M. (1941).
The Geology Of Benkoelen And The Oil - Possibilities .
Bandung:
Pusat Sumber Daya Geologi.
Gaya MLA
E., J.G.H., UBAGHS,, M..
"The Geology Of Benkoelen And The Oil - Possibilities".
Bandung:
Pusat Sumber Daya Geologi,
1941.
Bukan Logam.