APA (7e ed.) Bronvermelding

Não informado. (1991). Environment watch. Cutter Information.

Chicago (17e ed.) Bronvermelding

Não informado. Environment Watch. Arlington, Mass: Cutter Information, 1991.

MLA (8e ed.) Bronvermelding

Não informado. Environment Watch. Cutter Information, 1991.

Let op: Deze citaties zijn niet altijd 100% accuraat.