1. The bacteriology of activated sludge;Allen;J. Hyg., Camb.,1944
2. Standard methods for the examination of water and wastewater;American Public Health Association,1960
3. Amino acids in treated sewage in India;Anandeswara Sastry;Sewage ind. Wastes,1958
4. Ciliates in sludge;Anon;Nature, Lond.,1969
5. Techniques in protein chemistry;Bailey,1962