1. American Public Health Association. 1960. Standard methods for the examination of dairy products 11th ed. American Public Health Association Inc. New York.
2. American Public Health Association American Water Works Association and Water Pollution Control Federation. 1965. Standard methods for examination of water and wastewater 12th ed. American Public Health Association Inc. New York.
3. American Public Health Association Subcommittee on Methods for the Microbiological Examination of Foods. 1966. Recommended methods for the microbiological examination of foods 2nd ed. American Public Health Association Inc. New York.
4. The significance of various organisms of faecal origin in foods and drinking water;Buttiaux R.;J. Appl. Bacteriol.,1961
5. Antibiotic-resistant coliforms in fresh and salt water;Feary R. W.;Arch. Environ. Health,1972