APA (7th ed.) Zitazioa

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

Chicago Style (17th ed.) Zitazioa

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

MLA (9th ed.) Zitazioa

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