H. Kwak, C. Lee, H. Park, and S. Moon. Proceedings of the 19th international conference on World wide web, page 591--600. New York, NY, USA, ACM, (2010)
D. Karger, and D. Quan. The Semantic Web - ISWC 2004: Third International Semantic Web Conference,Hiroshima, Japan, November 7-11, 2004. Proceedings, volume 3298 of #LNCS#, page 214-228. #Springer#, (2004)