APA

Swan M., Smith B., . (2001). Learner English. A teacher's guide to interference and other problems. Cambridge: Cambridge University Press.

Chicago

Swan M, Smith B, . 2001. Learner English. A teacher's guide to interference and other problems. Cambridge: Cambridge University Press.

Harvard

Swan M., Smith B., . (2001). Learner English. A teacher's guide to interference and other problems. Cambridge: Cambridge University Press.

MLA

Swan M, Smith B, . Learner English. A teacher's guide to interference and other problems. Cambridge: Cambridge University Press. 2001.