APA (7e ed.) Bronvermelding

organization of the petroleum exporting countries. (2017). annual report 2017. grasl druck & neue medien gmbh.

Chicago (17e ed.) Bronvermelding

organization of the petroleum exporting countries. Annual Report 2017. austria: grasl druck & neue medien gmbh, 2017.

MLA (9e ed.) Bronvermelding

organization of the petroleum exporting countries. Annual Report 2017. grasl druck & neue medien gmbh, 2017.

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