Gaya APA
Thorn, D., Napitupulu, M. (1976).
Management of grounwater irrigation projects .
Bandung:
Direktorat Sumber Daya Mineral.
Gaya MLA
Thorn, D.G.., Napitupulu, M..
"Management of grounwater irrigation projects".
Bandung:
Direktorat Sumber Daya Mineral,
1976.
Umum.