Okun, D. A., & Ernst, W. R. (1987). Community piped water supply systems in developing countries: A planning manual. World Bank.
Lua i Stíl Chicago (17ú heag.)Okun, Daniel Alexander, agus Walter R. Ernst. Community Piped Water Supply Systems in Developing Countries: A Planning Manual. Washington, D.C: World Bank, 1987.
Lua MLA (9ú heag.)Okun, Daniel Alexander, agus Walter R. Ernst. Community Piped Water Supply Systems in Developing Countries: A Planning Manual. World Bank, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.