Purpura, J. E. (2004). Assessing grammar. Cambridge University Press.
Cita Chicago (17th ed.)Purpura, James E. Assessing Grammar. Cambridge University Press, 2004.
Cita MLA (9th ed.)Purpura, James E. Assessing Grammar. Cambridge University Press, 2004.
Atenció: Aquestes cites poden no estar 100% correctes.