title: approximate computation of multidimensional aggregates of sparse data using wavelets. authors: min wang , jeffrey scott vitter. venue: sigmod conference. year: 1999
title: approximate query processing using wavelets. authors: kaushik chakrabarti , minos garofalakis , rajeev rastogi , kyuseok shim. venue: the vldb journal -- the international journal on very large data bases. year: 2001