@Inproceedings{ls_leimeister,
  author = {Blohm, I. and Ott, F. and Bretschneider, U. and Huber, M. and Rieger, M. and Glatz, F. and Koch, M. and Leimeister, J. M. and Krcmar, H.},
  title  = {Extending Open Innovation Platforms into the real world - 
Using Large Displays in Public Spaces},

  year   = {2010},
  number = {10},
  url    = {http://www.uni-kassel.de/fb7/ibwl/leimeister/pub/JML_197.pdf},

  const  = {\ text}
}
@Inproceedings{ls_leimeister,
  author = {Blohm, I. and Ott, F. and Bretschneider, U. and Huber, M. and Rieger, M. and Glatz, F. and Koch, M. and Leimeister, J. M. and Krcmar, H.},
  title  = {Extending Open Innovation Platforms into the real world - Using Large Displays in Public Spaces},

  year   = {2010},
  number = {10},
  url    = {http://pubs.wi-kassel.de/wp-content/uploads/2013/03/JML_248.pdf},

  const  = {\ text}
}
@Inproceedings{parra2009evaluation,
  author = {Parra, Denis and Brusilovsky, Peter},
  title  = {Evaluation of Collaborative Filtering Algorithms for Recommending Articles on CiteULike},

  year   = {2009},
  number = {},
  url    = {http://ceur-ws.org/Vol-467/paper5.pdf},

  const  = {\ text}
}
@Article{herlocker2004ecf,
  author = {Herlocker, J.L. and Konstan, J.A. and Terveen, L.G. and Riedl, J.T.},
  title  = {Evaluating collaborative filtering recommender systems},
  journal = {ACM Transactions on Information Systems},
  year   = {2004},
  number = {1},
  url    = {},

  const  = {\ text}
}
@Article{Herlocker:2004:ECF:963770.963772,
  author = {Herlocker, Jonathan L. and Konstan, Joseph A. and Terveen, Loren G. and Riedl, John T.},
  title  = {Evaluating collaborative filtering recommender systems},
  journal = {ACM Trans. Inf. Syst.},
  year   = {2004},
  number = {},
  url    = {http://doi.acm.org/10.1145/963770.963772},
  doi = {10.1145/963770.963772},
  const  = {\ text}
}
@Article{herlocker2004evaluating,
  author = {Herlocker, Jonathan L. and Konstan, Joseph A. and Terveen, Loren G. and Riedl, John T.},
  title  = {Evaluating collaborative filtering recommender systems},
  journal = {ACM Trans. Inf. Syst.},
  year   = {2004},
  number = {1},
  url    = {http://portal.acm.org/citation.cfm?id=963770.963772},
  doi = {http://doi.acm.org/10.1145/963770.963772},
  const  = {\ text}
}