APA (7th ed.) Citation

World Health Organization & World Health Organization. (1990). International travel and health: Vaccination requirements and health advice, situation as on 1 January 1990. World Health Organization.

Chicago Style (17th ed.) Citation

World Health Organization and World Health Organization. International Travel and Health: Vaccination Requirements and Health Advice, Situation as on 1 January 1990. Geneva: World Health Organization, 1990.

MLA (9th ed.) Citation

World Health Organization and World Health Organization. International Travel and Health: Vaccination Requirements and Health Advice, Situation as on 1 January 1990. World Health Organization, 1990.