APA (7th ed.) Citation

Gale Research Inc. (1990). Ward's business directory of U.S. private and public companies. Gale Research.

Chicago Style (17th ed.) Citation

Gale Research Inc. Ward's Business Directory of U.S. Private and Public Companies. Detroit: Gale Research, 1990.

MLA (8th ed.) Citation

Gale Research Inc. Ward's Business Directory of U.S. Private and Public Companies. Gale Research, 1990.