Swan, M., & Smith, B. (2001). Learner English: A teacher's guide to interference and other problems (2nd ed.). Cambridge University Press.
Cita Chicago (17th ed.)Swan, Michael, i Bernard Smith. Learner English: A Teacher's Guide to Interference and Other Problems. 2nd ed. Cambridge ; New York: Cambridge University Press, 2001.
Cita MLA (8th ed.)Swan, Michael, i Bernard Smith. Learner English: A Teacher's Guide to Interference and Other Problems. 2nd ed. Cambridge University Press, 2001.
Atenció: Aquestes cites poden no estar 100% correctes.