1. Standard Methods for the Examination of Water and Wastewater;American Public Health Association (APHA),1995
2. The species distribution of some naturally occurring quaternary ammonium compounds;Beer;Comp. Biochem. Physiol.,1967
3. Consider biofiltration for decontaminating gases;Bohn;Chem. Engin. Prog.,1992
4. The distribution and possible taxonomic significance of quaternary ammonium and other dragend off positive compounds in some genera of marine algae;Bluden;Bot. Mar.,1982
5. Biofiltration for Air Pollution Control;Devinny,1999