Treatment of water of swimming pools and baths – Part 3: Combinations of process with ozonization
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 11/01/2012

Treatment of water of swimming-pools and baths – Part 3: Combination of process: Flocculation, filtration, ozonization, absorbing filtration, chlorination
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 04/01/1997