APA (7th ed.) Citation

World Book, I. (1996). The world book encyclopedia: W- x-y-z. World Book.

Chicago Style (17th ed.) Citation

World Book, Inc. The World Book Encyclopedia: W- X-y-z. Chicago: World Book, 1996.

MLA (9th ed.) Citation

World Book, Inc. The World Book Encyclopedia: W- X-y-z. World Book, 1996.