(1969). Steps to spoken english: A graded course for spanish-speaking students. Longman.
Čikaški stil citiranja (17. izdanje)Steps to Spoken English: A Graded Course for Spanish-speaking Students. London: Longman, 1969.
MLA način citiranja (9. izdanje)Steps to Spoken English: A Graded Course for Spanish-speaking Students. Longman, 1969.
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