APA (7th ed.) Citation

Walton, R., & O'Connell, S. (1996). Advanced english: CAE grammar practice. Longman.

Chicago Style (17th ed.) Citation

Walton, Richard, and Sue O'Connell. Advanced English: CAE Grammar Practice. Essex, Inglaterra: Longman, 1996.

MLA (9th ed.) Citation

Walton, Richard, and Sue O'Connell. Advanced English: CAE Grammar Practice. Longman, 1996.