Yorkey, R. C. (1977). English for international communication. Jilid 2. American Book.
Čikaški stil citiranja (17. izdanje)Yorkey, Richard C. English for International Communication. Jilid 2. American Book, 1977.
MLA način citiranja (8. izdanje)Yorkey, Richard C. English for International Communication. Jilid 2. American Book, 1977.
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