Não informado. (1976). Water quality bulletin. World Health Organization, Collaborating Centre on Surface and Ground Water.
Citação do estilo Chicago (17ª ed.)Não informado. Water Quality Bulletin. Ontario, Canada: World Health Organization, Collaborating Centre on Surface and Ground Water, 1976.
Citação MLA (8ª ed.)Não informado. Water Quality Bulletin. World Health Organization, Collaborating Centre on Surface and Ground Water, 1976.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.