APA (7th ed.) Zitazioa
(2009). Clean, Green and Blue: Singapore's Journey Towards Environmental and Water Sustainability. [s.n.].
Chicago Style (17th ed.) Zitazioa
Clean, Green and Blue: Singapore's Journey Towards Environmental and Water Sustainability. [S.l.]: [s.n.], 2009.
MLA (9th ed.) Zitazioa
Clean, Green and Blue: Singapore's Journey Towards Environmental and Water Sustainability. [s.n.], 2009.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.