APA Format
World Health Organization (WHO) . (). Principles for evaluating chemical effects on the aged population. : Genava WHO 1993
MLA Format
World Health Organization (WHO) . Principles for evaluating chemical effects on the aged population. : Genava WHO 1993,
Australian/Harvard Format
World Health Organization (WHO) . . Principles for evaluating chemical effects on the aged population. Genava WHO 1993, 
Warning: These citations may not always be 100% accurate.