Walker, E., & Elsworth, S. (2000). Grammar practice for upper intermediate students. England: Longman.
Chicago Style CitationWalker, Elaine., i Steve Elsworth. Grammar Practice for Upper Intermediate Students. England: Longman, 2000.
Cita MLAWalker, Elaine., i Steve Elsworth. Grammar Practice for Upper Intermediate Students. England: Longman, 2000.
Atenció: Aquestes cites poden no estar 100% correctes.