Great Britain. Dept. of the Environment & Great Britain. Welsh Office. (1975). River pollution survey of England and Wales, updated 1973: River quality and discharges of sewage and industrial effluents. H.M.S.O..
Lua i Stíl Chicago (17ú heag.)Great Britain. Dept. of the Environment agus Great Britain. Welsh Office. River Pollution Survey of England and Wales, Updated 1973: River Quality and Discharges of Sewage and Industrial Effluents. London: H.M.S.O., 1975.
Lua MLA (8ú heag.)Great Britain. Dept. of the Environment agus Great Britain. Welsh Office. River Pollution Survey of England and Wales, Updated 1973: River Quality and Discharges of Sewage and Industrial Effluents. H.M.S.O., 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.