1. R. Pujol, M. Hamon, X Kandel: Biofilters: Flexible, reliable biological reactors. Wat. Sci. & Technol. Vol. 10~11(1994), p.33.
2. R. Pujol: Process improvements for upflow submerged biofilters. Water21. Vol. 4(2000), p.25.
3. J. J. Chen, D. McCarty, D. Slack: Full scale studies of a simplified aerated filter (BAF) for organic and a nitrogen removal. Wat. Sci. & Technol. Vol. 4~5(2000), pp.1-4.
4. L. P Qiu: Research on operational characteristics of biological aerated filter (BAF) for domestic wastewater treatment and it ecology. Doctoral paper, Harbin institute of technology. (2003).
5. J. Ma, L.P. Qiu: Biological aerobic filter and its research progress. Environmental Engineering (in Chinese). Vol. 3 (2002), p.7.