Yucai Feng Wenhai Li Zehua Lv Xiaoming Ma Probabilistic Approximation under Incomplete Information Systems. 73-80 2006 Intelligent Information Processing http://dx.doi.org/10.1007/978-0-387-44641-7_8 conf/ifip12/2006iip db/conf/ifip12/iip2006.html#FengLLM06