APA (7th ed.) Zitazioa
Gatenby, E. V. (1960). A direct Method English Course (1a. ed.). Longman.
Chicago Style (17th ed.) Zitazioa
Gatenby, E. V. A Direct Method English Course. 1a. ed. Hong Kong: Longman, 1960.
MLA (9th ed.) Zitazioa
Gatenby, E. V. A Direct Method English Course. 1a. ed. Longman, 1960.
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