1. U.S. EPA, EPA History: Federal Water Pollution Control Act Amendments of 1972, U.S. Environmental Protection Agency, http://www2.epa.gov/aboutepa/epa-history-federal-water-pollution-control-act-amendments-1972. Accessed 2015
2. Ruchhoft E (1939) Public Health Rep 54(12)
3. Mickinney (1960) Proc. 3rd Conf. on Biological Waste Treatment. Manhattan College
4. Stainer (1963) The Microbial World, 2nd edn. Prentice-Hall
5. Mickinney RE (1962) Microbiology for sanitary engineers. McGraw-Hill, New York