1. RANITIDINE: less likelihood of mental confusion than with cimetidine?
2. Analysis "Problem" No. 15
3. Besides putting the friction of money into the equation, another development was critical for displaying better search results: the use of hypertext that, ideally, is not controlled by website owners, see: M Marchiori, 'The Quest for Correct Information on the Web: Hyper Search Engines' [1997] 29 Computer Networks and ISDN Systems 1225, 1227. The Google search engine was the first big search engine to employ this technique, see: S Brin and L Page;Bj Jansen;Adversarial Information Retrieval Aspects of Sponsored Search,2006
4. Sponsored Search: A Brief History;J O Dc Fain;Bulletin-American Society for Information Science and Technology,2006