1. Beijing Academy of Environmental Sciences, etc., 1998. Research report: compounding environmental protection policy study for developing gas fuel in Beijing. Beijing EPB, Beijing.
2. Beijing Statistical Bureau, 2001. Beijing Statistical Year Book 2000, Statistics Press, Beijing, China.
3. The evaluation of economic damage from atmospheric pollution in Chongqing;Chang,1996
4. Probing into energy policy oriented to sustainable development in China;Chen;Energy Engineer,1999
5. Chongqing Gas Corporation Ltd., etc., 1998. Project Proposal for Chongqing Urban Small–Medium Boilers and Cooking Range Reconstruction. Chongqing Gas Corporation Ltd., Chongqing.