[Aspects of water hygiene in the development of ponds left after open-cast mining into lakes suited for bathing].
D001493:Bathing Beaches; D005618:Fresh Water; D005859:Germany, East; D008906:Mining; D012499:Sanitation; D014867:Water; D014876:Water Pollution
D014867:Water
Wasserhygienische Aspekte bei der Entwicklung von kleineren Tagebaurestlöchern zu Badeseen.