Clarke, D., & Macfarlane, M. (2007). Focus on Business Workbook (New edition.). Cornelsen.
Lua i Stíl Chicago (17ú heag.)Clarke, David, agus Michael Macfarlane. Focus on Business Workbook. New edition. Berlin: Cornelsen, 2007.
Lua MLA (8ú heag.)Clarke, David, agus Michael Macfarlane. Focus on Business Workbook. New edition. Cornelsen, 2007.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.