Masaaki Narita Makoto Haraguchi Yoshiaki Okubo Data Abstractions for Numerical Attributes in Data Mining. 35-42 2002 conf/ideal/2002 IDEAL http://link.springer.de/link/service/series/0558/bibs/2412/24120035.htm db/conf/ideal/ideal2002.html#NaritaHO02