1. Standard methods for the examination of water and wastewater;American Public Health Association,1971
2. Environmental factors correlated with size of bacterial populations in a polluted stream;Brashfield;Appl. Microbiol.,1971
3. Microbiological examination of Sebeel water;Hamad;Appl. Environ. Microbiol.,1982
4. How plants can aid to improve water quality. Traditional methods in African countries and modern approach in the west;Jahn,1977