Sheldon, C., & Yoxon, M. (2007). Environmental management systems: A step-by-step guide to implementation and maintenance (3rd ed.). Earthscan.
Chicago-referens (17:e uppl.)Sheldon, Christopher, och Mark Yoxon. Environmental Management Systems: A Step-by-step Guide to Implementation and Maintenance. 3rd ed. London ; Sterling, VA: Earthscan, 2007.
MLA-referens (8:e uppl.)Sheldon, Christopher, och Mark Yoxon. Environmental Management Systems: A Step-by-step Guide to Implementation and Maintenance. 3rd ed. Earthscan, 2007.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.