1. SDWA: The Safe Drinking Water Act of 1974. Public Law 93-523. December 16, 1974.
2. EU (The Council of the European Union): Council Directive 75/440/EEC on the Quality of Water Intended for Human Consumption. Brussels, Belgium. December 19, 1997.
3. Giardia and Cryptosporidium spp. in filtered drinking water supplies
4. Center for Disease Control and Prevention (CDC): Cryptosporidiosis (Fact Sheet). National Center of Infectious Diseases, Division of Parasitic Diseases, Atlanta, GA, USA, 1995.
5. : Human coccidial infections. In: (Eds.): Tropical and Geographical Medicine. 2nd Edition. McGraw-Hill, Columbus, OH, 1990.