APA (7th ed.) Citation

Powell, D., & Walker, E. (2008). Grammar practice for upper intermediate students: With key (Third edition.). Pearson.

Chicago Style (17th ed.) Citation

Powell, Debra, and Elaine Walker. Grammar Practice for Upper Intermediate Students: With Key. Third edition. Harlow [England]: Pearson, 2008.

MLA (8th ed.) Citation

Powell, Debra, and Elaine Walker. Grammar Practice for Upper Intermediate Students: With Key. Third edition. Pearson, 2008.