APA (7th ed.) Citation

Yorkey, R. C. (1984). New Intercom: Workbook (3rd ed.). Heinle and Heinle.

Chicago Style (17th ed.) Citation

Yorkey, Richard C. New Intercom: Workbook. 3rd ed. Boston: Heinle and Heinle, 1984.

MLA (9th ed.) Citation

Yorkey, Richard C. New Intercom: Workbook. 3rd ed. Heinle and Heinle, 1984.