APA (7th ed.) Zitazioa
Energy Equipment & Services Industry Profile: Belgium. Marketline.
Chicago Style (17th ed.) Zitazioa
Energy Equipment & Services Industry Profile: Belgium. Marketline.
MLA (9th ed.) Zitazioa
Energy Equipment & Services Industry Profile: Belgium. Marketline.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.