Cita APA

Powell, D., Walker, E. 1., & Elsworth, S. P. B. 1. (2008). Grammar practice: For upper intermediates students with key (Thrid edition.). England: Pearson/Longman.

Citación estilo Chicago

Powell, Debra, Elaine 1960- Walker, y Steve Patrick Brendan 1952- Elsworth. Grammar Practice: For Upper Intermediates Students With Key. Thrid edition. England: Pearson/Longman, 2008.

Cita MLA

Powell, Debra, Elaine 1960- Walker, y Steve Patrick Brendan 1952- Elsworth. Grammar Practice: For Upper Intermediates Students With Key. Thrid edition. England: Pearson/Longman, 2008.