Não informado. (1986). Water & wastewater international. PY Publishing.
Lua i Stíl Chicago (17ú heag.)Não informado. Water & Wastewater International. Houston, Tex: PY Publishing, 1986.
Lua MLA (8ú heag.)Não informado. Water & Wastewater International. PY Publishing, 1986.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.