Không rõ. (2003). Cambridge first certificate examination practice 1: University of Cambridge Local Examinations Syndicate. TP Hồ Chí Minh.
استشهاد بنمط شيكاغوKhông rõ. Cambridge First Certificate Examination Practice 1: University of Cambridge Local Examinations Syndicate. TP Hồ Chí Minh, 2003.
MLA استشهادKhông rõ. Cambridge First Certificate Examination Practice 1: University of Cambridge Local Examinations Syndicate. TP Hồ Chí Minh, 2003.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.