World Health Organization & ebrary, Inc. (2007). Prevention. World Health Organization.
Cita Chicago (17th ed.)World Health Organization i Inc ebrary. Prevention. Geneva, Switzerland: World Health Organization, 2007.
Cita MLA (9th ed.)World Health Organization i Inc ebrary. Prevention. World Health Organization, 2007.
Atenció: Aquestes cites poden no estar 100% correctes.