Hadfield, J., & Hadfield, C. (1999). Simple speaking activities. Oxford: Oxford University Press.
Trích dẫn kiểu ChicagoHadfield, Jill, và Charles Hadfield. Simple Speaking Activities. Oxford: Oxford University Press, 1999.
MLA引文Hadfield, Jill, và Charles Hadfield. Simple Speaking Activities. Oxford: Oxford University Press, 1999.
警告：這些引文格式不一定是100％准確.