Penn, J. (2009). Family and friends teacher's book 1. Oxford University Press.
Trích dẫn kiểu ChicagoPenn, Julie. Family and Friends Teacher's Book 1. Oxford University Press, 2009.
MLA引文Penn, Julie. Family and Friends Teacher's Book 1. Oxford University Press, 2009.
警告：這些引文格式不一定是100％准確.