The Economist Intelligence Unit. (1999). Best practices: Environment. Univerties Press.
Čikaški stil citiranja (17. izdanje)The Economist Intelligence Unit. Best Practices: Environment. India: Univerties Press, 1999.
MLA način citiranja (8. izdanje)The Economist Intelligence Unit. Best Practices: Environment. Univerties Press, 1999.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.