@PhdThesis{Portabella2007thesis,
  author =      {Portabella, David},
  title =       {Improving User Confidence in Decision Support Systems for Electronic Catalogs},
  school =      {Swiss Federal Institute of Technology (EPFL)},
  year =        {2007},
  address =     {Lausanne (Switzerland)},
  type =        {PhD. Thesis No. 3737},
  bibtex_key =  {Portabella2007thesis},
  url =         {http://david.portabella.name/files/EPFL_TH3737.pdf}
}