Gaya APA

SOMMEN, J, V, D, S, H, S, D, F. (1990). Application of geographical information system in water resources management in Indonesia . : Iwaco.

Gaya MLA

SOMMEN, JJ, Van, Der;, SETIADI,, Hanady, S.;, DIRKS,, F.J.H.. "Application of geographical information system in water resources management in Indonesia". : Iwaco, 1990. Laporan.