E-commerce and web technologies : 7th international conference, EC-Web 2006, Krakow, Poland, September 5-7, 2006 / proceedings ; Kurt Bauknecht, Birgit Pröll, Hannes Werthner (eds.). - Bauknecht, Kurt, 1936-; Pröll, Birgit; Werthner, Hannes, 1954- (Lecture notes in computer science, 2006)