V. Richard Benjamins John Davies Ricardo A. Baeza-Yates Peter Mika Hugo Zaragoza Mark Greaves Jose Manuél Gómez-Pérez Jesús Contreras John Domingue Dieter Fensel 76-88 2008 23 IEEE Intelligent Systems 1 http://doi.ieeecomputersociety.org/10.1109/MIS.2008.10 db/journals/expert/expert23.html#BenjaminsDBMZGGCDF08