APA (7th ed.) Citation

THE WORLD BOOK ENCYCLOPEDIA. (1989). The world book encyclopedia: Research guide/index. World Book.

Chicago Style (17th ed.) Citation

THE WORLD BOOK ENCYCLOPEDIA. The World Book Encyclopedia: Research Guide/index. Chicago: World Book, 1989.

MLA (9th ed.) Citation

THE WORLD BOOK ENCYCLOPEDIA. The World Book Encyclopedia: Research Guide/index. World Book, 1989.

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