@inproceedings{schmitz06,
  author = {Schmitz, Patrick},
  booktitle = {Collaborative Web Tagging Workshop at WWW2006, Edinburgh, Scotland},
  interhash = {1335f4ef87f951e6edf4fd94f885d3a2},
  intrahash = {77143fd854a06583430afae1371fad71},
  month = May,
  title = {Inducing Ontology from Flickr Tags.},
  url = {http://www.ibiblio.org/www_tagging/2006/22.pdf},
  year = 2006
}

@techreport{citeulike:739394,
  abstract = {Collaborative tagging systems---systems where many casual users annotate objects with free-form strings (tags) of their choosing---have recently emerged as a powerful way to label and organize large collections of data. During our recent investigation into these types of systems, we discovered a simple but remarkably effective algorithm for converting a large corpus of tags annotating objects in a tagging system into a navigable hierarchical taxonomy of tags. We first discuss the algorithm and then present a preliminary model to explain why it is so effective in these types of systems.},
  author = {Heymann, Paul and Garcia-Molina, Hector},
  citeulike-article-id = {739394},
  institution = {Computer Science Department},
  interhash = {d77846b40aadb0e25233cabf905bb93e},
  intrahash = {3b4ce6fd7fa6dbf1c39fd261fa39fcd6},
  month = {April},
  number = {2006-10},
  priority = {3},
  school = {Standford University},
  title = {Collaborative Creation of Communal Hierarchical Taxonomies in Social Tagging Systems},
  url = {http://dbpubs.stanford.edu:8090/pub/2006-10},
  year = 2006
}