Clarke, D., & Macfarlane, M. (2007). Focus on Business Workbook (New edition.). Cornelsen.
Chicago-Zitierstil (17. Ausg.)Clarke, David, und Michael Macfarlane. Focus on Business Workbook. New edition. Berlin: Cornelsen, 2007.
MLA-Zitierstil (8. Ausg.)Clarke, David, und Michael Macfarlane. Focus on Business Workbook. New edition. Cornelsen, 2007.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.