APA (7th ed.) Zitazioa

Ur, P. (1989). Grammar practice activities: A practical guide for teachers. Univ. Pr.

Chicago Style (17th ed.) Zitazioa

Ur, Penny. Grammar Practice Activities: A Practical Guide for Teachers. Cambridge: Univ. Pr, 1989.

MLA (9th ed.) Zitazioa

Ur, Penny. Grammar Practice Activities: A Practical Guide for Teachers. Univ. Pr, 1989.