Doff, A., & Jones, C. (1997). Language in use: Upper-intermediate : self-study workbook [Băng Casset]. Cambridge: Cambridge U. P..
Παραπομπή Chicago StyleDoff, Adrian, και Christopher Jones. Language in Use: Upper-intermediate : Self-study Workbook [Băng Casset]. Cambridge: Cambridge U. P., 1997.
Παραπομπή MLADoff, Adrian, και Christopher Jones. Language in Use: Upper-intermediate : Self-study Workbook [Băng Casset]. Cambridge: Cambridge U. P., 1997.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.