1. Review: Waste gas biotreatment technology
2. (1997). Biological waste gas treatment: A competitive alternative, Proceedings of an International Symposium, Maastricht, The Netherlands (pp. 1-4), April 28-29, Düsseldorf, Germany: VDI Verlag.
3. & (1994). Control of hazardous air pollutants using a commercial biofilter, Proceedings of 87th Annual Meeting and Exhibition of Air & Waste Management Association, Cincinnati, OH, June 19-24, Paper WA74A.02.
4. Biological treatment of airstreams contaminated with VOCs: an overview
5. & (2003). Commercial application of air phase biofilters. http://www.ppcbio.com/ppcbiopaper1.htm (accessed February 2003).