APA Format
World Health Organization (WHO) . (). Gestational trophoblastis diseases, TRS.692. : Geneva WHO 1983
MLA Format
World Health Organization (WHO) . Gestational trophoblastis diseases, TRS.692. : Geneva WHO 1983,
Australian/Harvard Format
World Health Organization (WHO) . . Gestational trophoblastis diseases, TRS.692. Geneva WHO 1983, 
Warning: These citations may not always be 100% accurate.