APA (7th ed.) Citation

OPEC. (2018). Annual statistical bulletin. [Verlag nicht ermittelbar].

Chicago Style (17th ed.) Citation

OPEC. Annual Statistical Bulletin. Vienna: [Verlag nicht ermittelbar], 2018.

MLA (9th ed.) Citation

OPEC. Annual Statistical Bulletin. [Verlag nicht ermittelbar], 2018.

Warning: These citations may not always be 100% accurate.