Ur, P. (1989). Grammar practice activities: A practical guide for teachers. Univ. Pr.
Citazione stile Chigago Style (17a edizione)Ur, Penny. Grammar Practice Activities: A Practical Guide for Teachers. Cambridge: Univ. Pr, 1989.
Citatione MLA (9a ed.)Ur, Penny. Grammar Practice Activities: A Practical Guide for Teachers. Univ. Pr, 1989.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.