APA (7th ed.) Zitazioa
Eckersley, C. E. (1951). Essential english: Book one. Longman.
Chicago Style (17th ed.) Zitazioa
Eckersley, C. E. Essential English: Book One. London: Longman, 1951.
MLA (9th ed.) Zitazioa
Eckersley, C. E. Essential English: Book One. Longman, 1951.
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