@Inproceedings{auyeung2009measuring,
  author = {{Au Yeung}, Ching Man and Noll, Michael G. and Gibbins, Nicholas and Meinel, Christoph and Shadbolt, Nigel},
  title  = {On Measuring Expertise in Collaborative Tagging Systems},

  year   = {2009},
  number = {},
  url    = {http://journal.webscience.org/109/},

  const  = {\ text}
}
@Article{oezsu2009encyclopedia,
  author = {Özsu, M. Tame and Liu, Lin},
  title  = {Encyclopedia of database systems},

  year   = {2009},
  number = {},
  url    = {http://www.worldcat.org/search?qt=worldcat_org_all&q=9780387496160},

  const  = {\ text}
}
@Inproceedings{krause2008antisocialb,
  author = {Krause, Beate and Schmitz, Christoph and Hotho, Andreas and Stumme, Gerd},
  title  = {The Anti-Social Tagger - Detecting Spam in Social Bookmarking Systems},

  year   = {2008},
  number = {},
  url    = {http://airweb.cse.lehigh.edu/2008/submissions/krause_2008_anti_social_tagger.pdf},

  const  = {\ text}
}