Cita APA (7th ed.)

Webster, D. (1981). Keep listening: Study guide (1a. ed.). Longman.

Cita Chicago (17th ed.)

Webster, Diana. Keep Listening: Study Guide. 1a. ed. Harlow: Longman, 1981.

Cita MLA (9th ed.)

Webster, Diana. Keep Listening: Study Guide. 1a. ed. Longman, 1981.