Cita APA (7th ed.)

Ur, P. (2009). Grammar practice activities: A practical guide for teachers (Second edition.). Cambridge University Press.

Cita Chicago (17th ed.)

Ur, Penny. Grammar Practice Activities: A Practical Guide for Teachers. Second edition. Cambridge: Cambridge University Press, 2009.

Cita MLA (9th ed.)

Ur, Penny. Grammar Practice Activities: A Practical Guide for Teachers. Second edition. Cambridge University Press, 2009.