1. Environmental purchasing and firm performance: An empirical investigation;Carter;Transportation Research Part E,2000
2. Chen , J. 2005 Personal communication with Jian Chen, Vice Director of Buitang Group, Nanning, China, May 2005
3. Chen , J. 2006 Personal communication with Jian Chen, Vice Director of Buitang Group, Nanning, China, January 2006
4. Industrial symbiosis: Literature and taxonomy;Chertow;Annual Review of Energy and the Environment,2000