APA (7th ed.) Citation

Berens, J., & Berens, J. (1969). Commercial radio operator's license study guide. Chilton Book Co..

Chicago Style (17th ed.) Citation

Berens, Julius, and Jack Berens. Commercial Radio Operator's License Study Guide. Philadelphia: Chilton Book Co., 1969.

MLA (9th ed.) Citation

Berens, Julius, and Jack Berens. Commercial Radio Operator's License Study Guide. Chilton Book Co., 1969.