(1999). Life lines 1: Pre- Intermediate. Oxford: Oxford University Press.
Trích dẫn kiểu ChicagoLife Lines 1: Pre- Intermediate. Oxford: Oxford University Press, 1999.
MLA引文Life Lines 1: Pre- Intermediate. Oxford: Oxford University Press, 1999.
警告：這些引文格式不一定是100％准確.