@Article{Hofmann2004,
  author = {Thomas Hofmann},
  title  = {Latent semantic models for collaborative filtering},
  journal = {ACM Transactions on Information Systems (TOIS)},
  year   = {2004},
  number = {1},
  url    = {http://doi.acm.org/10.1145/963770.963774},

  const  = {\ text}
}
@Inproceedings{papadimitriou98latent,
  author = {Christos H. Papadimitriou and Hisao Tamaki and Prabhakar Raghavan and Santosh Vempala},
  title  = {Latent Semantic Indexing: A Probabilistic Analysis},

  year   = {1998},
  number = {},
  url    = {citeseer.ist.psu.edu/papadimitriou98latent.html},

  const  = {\ text}
}