The ten volumes of A COMPLETE CONCORDANCE TO THE WORKS OF GEOFFREY CHAUCER make possible systematic studies of Chaucer’s language and text for the first time. They have a great potential as a standard research tool for English medievalists, historians of the language and historians of ideas. They allow students of Chaucer's syntax to analyse common and “high-frequency” words in their contexts. The Concordance is based on the Riverside Chaucer published under the general editorship of Larry d. Benson (Boston 1987, and Oxford 1988). The two volumes of A RHYME CONCORDANCE TO THE POETICAL WORKS OF GEOFFREY CHAUCER are a sequel to the Concordance. The Rhyme Concordance is the first of its kind. The five volumes of A LEXICAL CON¬CORDANCE TO THE WORKS OF GEOFFREY CHAUCER are a sequel to the Concordance as well. A Lexical Concordance To The Works Of Geoffrey Chaucer is lemmatized and largely based on the Middle English Dictionary, all morphologically variant forms of a word are gathered under a convenient heading, as in most dictionaries.