1. Studies on the status and management strategies for general industrial solid wastes of Ningxia;Ren;Northern environment,2011
2. People's Republic of China Ministry of Environmental Protection Comprehensive environmental statistics reporting system 2009,10.
3. China Environment Yearbook;Yang,2011
4. Sina Finance. Our problem tailings ponds reached 2369, a major hazard to environment. http://finance.sina.com.cn/china/20140818/130120043071.shtml.
5. National development and reform commission. China resources comprehensive utilization annual report (2014). Beijing:2014: 5, 9-10.