O'Connell, S. (2002). Focus on IELTS. London: Pearson education.
Trích dẫn kiểu ChicagoO'Connell, Sue. Focus On IELTS. London: Pearson education, 2002.
MLA引文O'Connell, Sue. Focus On IELTS. London: Pearson education, 2002.
警告：这些引文格式不一定是100％准确.
APA引文