1. E. Ruchhoft, Public Health Reports 54, no. 12 (1939).
2. Mickinncy,Proc. Third Conf. on Biological Waste Treatment, Manhattan College. 1960.
3. Stainer, The Microbial World, 2nd edition, Prentice-Hall. 1963.
4. Mickinney,Microbiology for Sanitary- Engineers,McGraw-Hill, 1962.
5. McCorty, in Water Pollution Microbiology, ed. by Mitchell, R., Wiley-Interscience,1972.