APA (7th ed.) Citation

(1988). Smallpox and its eradication. World Health Organization.

Chicago Style (17th ed.) Citation

Smallpox and Its Eradication. Geneva: World Health Organization, 1988.

MLA (9th ed.) Citation

Smallpox and Its Eradication. World Health Organization, 1988.

Warning: These citations may not always be 100% accurate.