J. Yang, and J. Leskovec. Proceedings of the Sixth ACM International Conference on Web Search and Data Mining, page 587--596. New York, NY, USA, ACM, (2013)
W. Fury, F. Batliwalla, P. Gregersen, and W. Li. Engineering in Medicine and Biology Society, 2006. EMBS'06. 28th Annual International Conference of the IEEE, page 5531--5534. IEEE, (2006)