World Health Organization. (1998). Guidelines for drinking - water quality: Recommendations (2nd-edn.). World Health Organization.
Chicago Style aipamenaWorld Health Organization. Guidelines for Drinking - Water Quality: Recommendations. 2nd-edn. Geneva: World Health Organization, 1998.
MLA aipamenaWorld Health Organization. Guidelines for Drinking - Water Quality: Recommendations. 2nd-edn. World Health Organization, 1998.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.