Shailendra Singh Bhanu Prasad User Relevance Feedback Analysis in Text Information Retrieval: A Rough Set Approach. 147-178 2008 Soft Computing Applications in Business http://dx.doi.org/10.1007/978-3-540-79005-1_9 series/sfsc/2008-230 db/series/sfsc/sfsc230.html#SinghP08