A violin composition by Bach's eldest son Wilhelm Friedemann, transcribed for the organ by Ringk, was named as another possible source. However, according to 21st-century statistical analysis, Wilhelm Friedemann was even less likely to have been the composer of the Fugue than Kellner. The same research indicated that large portions of the Fugue were consistent with the style of Johann Ludwig Krebs, but with more than half of the Fugue more likely composed by J. S. Bach. After initially confirming Williams's doubts about the authorship of BWV 565, by the second decade of the 21st century, statistical analysis left the attribution issue undecided. No-one had found a composer more compatible with the style of its fugue than Bach himself. In the words of Jean-Claude Zehnder, who was sympathetic towards the violin version reconstruction: "The matter still remains open, despite the scholarly discourse that began in 1981. Until proof of the contrary, BWV 565 should be considered as a work by Johann Sebastian Bach." No edition of the Bach Werke Verzeichnis has listed BWV 565 among the works seen as spurious or doubtful, nor does the work's entry on the website of the Bach Archiv Leipzig mention any doubts.