John Clear Debbie Dunn Brad Harvey Michael L. Heytens Peter Lohman Abhay Mehta Mark Melton Lars Rohrberg Ashok Savasere Robert M. Wehrmeister Melody Xu NonStop SQL/MX Primitives for Knowledge Discovery. 425-429 1999 KDD http://doi.acm.org/10.1145/312129.312309 db/conf/kdd/kdd99.html#ClearDHHLMMRSWX99