1. APHA, 1989. Standard Methods for the Examination of Water and Wastewater, seventeenth ed. American Public Health Association, Washington, DC
2. APHA, 1992. Standard Methods for the Examination of Water and Wastewater, eighteenth ed. American Public Health Association, Washington, DC
3. Linear Statistical Models: An Applied Approach;Bowerman,1990
4. Practical Nonparametric Statistics;Conover,1980
5. Epidemiological studies of organic micropollutants in drinking water;Craun,1991