Não informado. (1992). Water & environment international. Argus Business Media.
Chicago (17e ed.) BronvermeldingNão informado. Water & Environment International. Surrey, Inglaterra: Argus Business Media, 1992.
MLA (8e ed.) BronvermeldingNão informado. Water & Environment International. Argus Business Media, 1992.
Let op: Deze citaties zijn niet altijd 100% accuraat.