@book{berendt2008challenge,,
  title = {Wikis, Blogs, Bookmarking Tools - Mining the Web 2.0 Workshop},
  publisher = {Workshop at 18th Europ. Conf. on Machine Learning (ECML'08) / 11th Europ. Conf. on Principles and Practice of Knowledge Discovery in Databases (PKDD'08)},
  year = {2008},
  url = {http://www.kde.cs.uni-kassel.de/ws/wbbtmine2008/pdf/all_wbbtmine2008.pdf}
}

@book{hotho2008challenge,,
  title = {ECML PKDD Discovery Challenge 2008 (RSDC'08)},
  publisher = {Workshop at 18th Europ. Conf. on Machine Learning (ECML'08) / 11th Europ. Conf. on Principles and Practice of Knowledge Discovery in Databases (PKDD'08)},
  year = {2008},
  url = {http://www.kde.cs.uni-kassel.de/ws/rsdc08/pdf/all_rsdc_v2.pdf}
}