1. Examination of well and Nile water;Abdel Magid;Environ. Int.,1984
2. Standard Methods for the Examination of Water and Wastewater;American Public Health Association,1971
3. Viral Pollution of the Environment;Berg,1983
4. United Nations Water Conference;Biswas,1978
5. Microbiological criteria for tropical water quality;Evison,1977