1. SZILARD, R.; ZIESING D.; PICKHARDT, S. BASIC-Programme für Baumechanik und Statik. Ernst Verlag, Berlin, 1986.
2. JÄGER P. Parametric Design of Post-tensioned Concrete Digesters. FIP Congress on Prestressed Concrete, Hamburg, 1990.
3. RSB-RUND-STAHL-BAU GmbH. RSB-Roundtech Formwork Systems. Fussach, Austria.
4. VORSPANN-TECHNIK GmbH. VT CMM-System. Salzburg, Austria.
5. JÄGER P. First Egg-Shaped Sludge Digesters Using Exclusively Unbonded Tendons. FIP Symposium, Kyoto, Japan, 1993.