@Inproceedings{becker00conceptual,
  author = {Becker, K. and Stumme, G. and Wille, R. and Wille, U. and Zickwolff, M.},
  title  = {Conceptual Information Systems Discussed Through an IT-Security Tool},

  year   = {2000},
  number = {},
  url    = {http://www.kde.cs.uni-kassel.de/stumme/papers/2000/EKAW00.pdf},

  const  = {\ text}
}
@Inproceedings{WilleZickwolff00Grundlagen,
  author = {Wille, R. and Zickwolff, M.},
  title  = {Grundlagen einer triadischen Begriffsanalyse},

  year   = {2000},
  number = {},
  url    = {},

  const  = {\ text}
}