Daniel Hladky Christian Ehrlich Irina Efimenko Vyacheslav Vorobyov Discover Shadow Groups from the Dark Web. 67-81 2010 Web Intelligence and Security - Advances in Data and Text Mining Techniques for Detecting and Preventing Terrorist Activities on the Web http://dx.doi.org/10.3233/978-1-60750-611-9-67 series/natosec/27 db/series/natosec/natosec27.html#HladkyEEV10