Purpura, J. E. (2013). Assessing grammar. Cambridge: Cambridge University Press.
Trích dẫn kiểu ChicagoPurpura, James E. Assessing Grammar. Cambridge: Cambridge University Press, 2013.
MLA引文Purpura, James E. Assessing Grammar. Cambridge: Cambridge University Press, 2013.
警告：这些引文格式不一定是100％准确.