1. Harremoës, P., Arvin, E., Henze, M.: Wastewater Nutrient Removal. Conference on Lake Pollution and recovery, Rome, April 1518, 1985
2. Fettig, J., Ratnaweera, H., Thorvaldsen, G.: Coagulation/Chemical Precipitation of Synthetic Wastewater with Different Chemicals. SINTEF report STF60 F89078, July 1989 (in Norwegian)
3. Eastman, J.A., Ferguson, J.F.: Solubilization of Particulate Organic Carbon During the Acid Phase of Anaerobic Digestion. J. WPCF 53 (1981) 352 - 366
4. Karlsson, I., Smith, G.: Pre-Precipitation Facilitates Nitrogen Removal Without Tank Expansion. Conference on Big Treatment Plants, Munich, 6 - 9 September 1989
5. Henze, M.: Carbon Sources for Denitrification from Wastewater. Seminar on Nutrients Removal from Municipal Wastewater, Tampere, Finland, 4–6 September 1989