APA (7th ed.) Citation

World Book, Inc, Barnhart, C. L., & Barnhart, R. K. (1991). The World Book dictionary. World Book.

Chicago Style (17th ed.) Citation

World Book, Inc, Clarence L. Barnhart, and Robert K. Barnhart. The World Book Dictionary. Chicago: World Book, 1991.

MLA (9th ed.) Citation

World Book, Inc, et al. The World Book Dictionary. World Book, 1991.