title: approximate computation of multidimensional aggregates of sparse data using wavelets. authors: min wang , jeffrey scott vitter. venue: sigmod conference. year: 1999
title: storage estimation for multidimensional aggregates in the presence of hierarchies. authors: amit shukla , prasad deshpande , jeffrey f. naughton , karthikeyan ramasamy. venue: very large data bases. year: 1996