Azar, B. S. (2009). Understanding and using English grammar: Workbook (Fourth Edition.). Longman.
Chicago Style (17. basım) AtıfAzar, Betty Schrampfer. Understanding and Using English Grammar: Workbook. Fourth Edition. Longman, 2009.
MLA (9th ed.) AtıfAzar, Betty Schrampfer. Understanding and Using English Grammar: Workbook. Fourth Edition. Longman, 2009.
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