1. APHA, 1989. Standard Methods for the Examination of Water and Wastewater, 16th Edition. American Public Health Association, American Water Works Association and Water Pollution Control Federation, Washington DC.
2. Appan, A., 1999. Economic and water quality aspects of rainwater catchment system. Proceedings of International Symposium on Efficient Water Use in Urban Areas. UNEP Int. Environ. Tech. Center, Osaka, Japan, 79pp.
3. Pollution assessment for organic chemicals in surface water of jingling section;Bao;Journal of Environmental Chemistry,1990
4. Fresenius, W., Quentin, K.E., Scheider, W., 1988. Water Analysis, Chinese Edition. Peking University Press, Beijing, China, 411pp.
5. Gansu Daily, 2003. Annual Report on Economic and Social Development of Gansu Province (issued January 18), Lanzhou, China.