Ehlers, V. M. Municipal and rural sanitation (4a ed.).
Lua i Stíl Chicago (17ú heag.)Ehlers, Víctor M. Municipal and Rural Sanitation. 4a ed.
Lua MLA (8ú heag.)Ehlers, Víctor M. Municipal and Rural Sanitation. 4a ed.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.