Powell, D., Walker, E., & Elsworth, S. (2008). Grammar practice for upper intermediate students (3rd ed.). Pearson Education Limited.
Chicago Style (17th ed.) CitationPowell, Debra, Elaine Walker, and Steve Elsworth. Grammar Practice for Upper Intermediate Students. 3rd ed. Harlow: Pearson Education Limited, 2008.
MLA (9th ed.) CitationPowell, Debra, et al. Grammar Practice for Upper Intermediate Students. 3rd ed. Pearson Education Limited, 2008.
Warning: These citations may not always be 100% accurate.