APA (7th ed.) Citation

Powell, D., Walker, E., & Elsworth, S. (2008). Grammar Practice for Upper Intermediate Students: With key (Third Edition.). Pearson Education Limited.

Chicago Style (17th ed.) Citation

Powell, Debra, Elaine Walker, and Steve Elsworth. Grammar Practice for Upper Intermediate Students: With Key. Third Edition. Essex, England: Pearson Education Limited, 2008.

MLA (9th ed.) Citation

Powell, Debra, et al. Grammar Practice for Upper Intermediate Students: With Key. Third Edition. Pearson Education Limited, 2008.