World Health Organization. (1995). International travel and health: Vaccination requirements and health advice. World Health Organization.
Cita Chicago (17th ed.)World Health Organization. International Travel and Health: Vaccination Requirements and Health Advice. Geneva: World Health Organization, 1995.
Cita MLA (8th ed.)World Health Organization. International Travel and Health: Vaccination Requirements and Health Advice. World Health Organization, 1995.
Atenció: Aquestes cites poden no estar 100% correctes.