Doff, A., & Jones, C. (1994). Language in use: Intermediate : self-study workbook with answer key [Băng Casset]. Cambridge: Cambridge U. P..

Doff, Adrian, و Christopher Jones. Language in Use: Intermediate : Self-study Workbook With Answer Key [Băng Casset]. Cambridge: Cambridge U. P., 1994.

Doff, Adrian, و Christopher Jones. Language in Use: Intermediate : Self-study Workbook With Answer Key [Băng Casset]. Cambridge: Cambridge U. P., 1994.