The Praeludium in E-moll, BWV 932 is one of the pieces that were left to us unfinished. It's a real shame, because it's such a nice and intimate keyboard piece (appropriate for both organ and harpsichord). Therefore there are some attempts to finished the piece by different composers.
Carson Cooman shared this score with me, in which Wolfgang Stockmeier finished this unfinished Bach piece. In his score the place was marked where Bach stopped and where Stockmeier continued. However, it's nice to try to detect that place yourself, since I think Stockmeier did a very fine job in finishing this piece. Of course you can search for the manuscript on the web and see for yourself where Bach stopped.