Ashwani Kumar D. P. Agrawal S. D. Joshi Multiscale rough set data analysis with application to stock performance modeling. 197-209 2004 8 Intell. Data Anal. 2 http://iospress.metapress.com/openurl.asp?genre=article&issn=1088-467X&volume=8&issue=2&spage=197 db/journals/ida/ida8.html#KumarAJ04