1. Google Web APIs 〈http://www.google.com/apis/〉, 2005.
2. XML Topic Maps 〈http://www.topicmaps.org/xtm/〉, 2005.
3. Tracking and summarizing news on a daily basis with Columbia's Newsblaster;McKeown,2002
4. A language modeling approach to tracking news events;Spitters,2002
5. Query-free news search;Henzinger,2003