Lex Mundi Guides to Doing Business. Members of the Lex Mundi international law firm network contributed these comprehensive and frequently updated guides to doing business in more than 100 countries, the European Union, and various U.S. states. Each guide is a detailed discussion of the jurisdiction’s government and commerce, its investment framework, its rules for importing and exporting, and forms of business organization, banking and trust companies, insurance law, taxation, visas and other important topics.