1. Preliminary Recommendations Concerning Dimensioning, Building and Operation of Retention Soil Filters for Combined Water Treatment in the Federal State of Hessia (Ed: Hessian State Ministry for Environment, HSME) 2002. http://www.hmulv.hessen.de/imperia/md/content/internet/pdfs/umwelt/wasser/vorl_empfehl_30_09_02.pdf
2. F.-B. Frechen, W. Schier, J. Felmeden, Plant-Covered Retention Soil Filters (RSF): Treatment for stormwater overflow from combined sewer systems, in Proc. of the 9th IWA Specialist Group Conf. on Wetlands Systems, Avignon 2004, Issue 2, 537–544.
3. Retention Soil Filters for Rainwater Treatment in Combined and Separate Systems (Ed: State Office for Environment Baden-Württemberg), Karlsruhe 2002.
4. Retention Soil Filters: Manual for Dimensioning, Building and Operation (Ed: State Ministry for Environment, Nature Conservation, Agriculture and Consumer Protection of North Rhine Westphalia), 2003.
5. Richtlinien für die Bemessung und Gestaltung von Regenentlastungsanlagen in Mischwasserkanälen (Arbeitsblatt-A 128, Standard), (Ed: German Association for Water, Wastewater and Waste, ATV), Hennef 1992.