1. The People’s Republic of China Yearbook 2007;Editorial office of China Yearbook,2008
2. The People’s Republic of China Yearbook 2008;Editorial office of China Yearbook,2009
3. AQSIQ, 2002. Collection of Standard Design Drawings for Household Anaerobic Digesters. GB/T 4750-2002.
4. Li, K., Ho, M.-W., 2006. Biogas China. ISIS Report 02/10/06. .
5. Ministry of Agriculture of the People’s Republic of China, (MOA), 2006. Technical Code for Biogas Engineering. NY/T 1220-2006.