Fees, quotas, documentation for cross-border processes and various types of international invoices make global sourcing a difficult challenge. Governments impose tariffs and quotas to raise revenue and make foreign goods expensive to protect national interests. Another example of governments' efforts to protect national interests is the imposition of numerous trade restrictions and bills. Cross-border procedures such as customs duties impose heavy restrictions on international trade. Exchange rates and currency fluctuations also pose a different set of problems. The main challenges also depend on the managerial and demographic characteristics of the company. US firms sourcing products from Germany will be less concerned about cultural difference than those sourcing from Japan (Czinkota and Ronkainen, 1993). And US companies that buy products from Europe and Canada will also be less worried about logistics than those that buy from East Asia due to physical distancing (Monczka and Giunipero