1. Nitrification in tertiary trickling filters followed by deep-bed filters;Boller;Wat. Res.,1986
2. Nitrification in the activated sludge process;Downing;J. Inst. Sewage Purif.,1964
3. Nitrit in Fliessgewässern;Gujer;Schweiz. Z. Hydrol.,1978
4. Operating experience with plastic media tertiary trickling filters for nitrification;Gujer,1983
5. The effects of diurnal ammonium load variation on the performance of nitrifying activated sludge processes;Gujer;Prog. Wat. Technol.,1978