title: the a-tree : an index structure for high-dimensional spaces using relative approximation. authors: y sakurai , m yoshikawa , s uemura , h kojima. venue: vldb. year: 2000
title: the x-tree : an index structure for highdimensional data . 2 & nd vldb. authors: s berchtold , da keim , hp kriegel. venue: mumbai ( bombay ) , india , sept ,. year: nan