APA Format
World Health Organization (WHO) . (). Health effects of interactions between tobacco use and exposure to other agents. : Geneva WHO 1999
MLA Format
World Health Organization (WHO) . Health effects of interactions between tobacco use and exposure to other agents. : Geneva WHO 1999,
Australian/Harvard Format
World Health Organization (WHO) . . Health effects of interactions between tobacco use and exposure to other agents. Geneva WHO 1999, 
Warning: These citations may not always be 100% accurate.