Adam Smith
Adam Smith emphasized the importance of specialization and division of labor. This page contains links to sites that provide information about Adam Smith and his work. Online editions of his major works are available from this page.

David Ricardo
David Ricardo developed the theory of comparative advantage. Information about David Ricardo and his work is available from this page.

E-Bay
This is the web site of the online auction site discussed in your text.

Internet Auction List
This site provides a list of a very large number of online auction sites.