Cita APA (7th ed.)
Ur, P. (1988). Grammar practice activities: A practical guide for teachers. CUP.
Cita Chicago (17th ed.)
Ur, Penny. Grammar Practice Activities: A Practical Guide for Teachers. Cambridge: CUP, 1988.
Cita MLA (9th ed.)
Ur, Penny. Grammar Practice Activities: A Practical Guide for Teachers. CUP, 1988.
Atenció: Aquestes cites poden no estar 100% correctes.