1. Bayer Tower Biology: E 589–777/68619.
2. LOPROX: a flexible way to pretreat poorly biodegradeable effluents;Holzer,1992
3. Holzer, K., 1999. AVT-Handbuch, Industriabwasser, Grundlagen, 4. Auflage, p 183 ff.
4. Tower-shaped reactors for aerobic biological waste water treatment;Zlokarnik,1985