Christie, D. (1999). Focus on Business: Workbook / [David Christie] (New edition.). Cornelsen & Oxford.
Chicago-Zitierstil (17. Ausg.)Christie, David. Focus on Business: Workbook / [David Christie]. New edition. Berlin: Cornelsen & Oxford, 1999.
MLA-Zitierstil (8. Ausg.)Christie, David. Focus on Business: Workbook / [David Christie]. New edition. Cornelsen & Oxford, 1999.
警告：这些引文格式不一定是100％准确.