13. The computer-implemented method of claim 12 , further comprising: for each reference item of the plurality of reference items, dividing at least one of a reference-item artist name or a reference-item title of each reference item into respective reference-item characters; and for each reference item of the plurality of reference items, canonicalizing the respective reference-item characters to remove punctuation and render the respective reference-item characters that remain in lowercase form.
14. The computer-implemented method of claim 13 , further comprising: determining whether a reference item contains at least a predetermined number of reference-item characters that match the respective characters for the at least one of the artist name or the title of the candidate item, for each reference item of a set of reference items; and selecting each reference item that contains the at least a predetermined number of reference-item characters that match the respective characters; and forming a plurality of reference items comprising the selected reference items.