Wulf, L. D. (2005). Customs modernization handbook. Wasington: The World Bank.
Trích dẫn kiểu ChicagoWulf, Luc De. Customs Modernization Handbook. Wasington: The World Bank, 2005.
MLA引文Wulf, Luc De. Customs Modernization Handbook. Wasington: The World Bank, 2005.
警告：这些引文格式不一定是100％准确.