APA

Harmer J., . (1997). The Practice of English Language Teaching. London: Longman.

Chicago

Harmer J, . 1997. The Practice of English Language Teaching. London: Longman.

Harvard

Harmer J., . (1997). The Practice of English Language Teaching. London: Longman.

MLA

Harmer J, . The Practice of English Language Teaching. London: Longman. 1997.