Four other early manuscripts also exist. One, originally identified as an authentic Bach autograph from his Leipzig period, is now identified as being a copy dating from 1727–32 by Bach's second wife Anna Magdalena Bach, and is the companion to her copy of the six suites Bach wrote for solo cello. Another copy, dated July 3, 1726 (the date is on the final page), made by one of Bach's admirers Johann Peter Kellner, is well preserved, despite the fact that the B minor Partita was missing from the set and that there are numerous deviations and omissions. These differences may have come from an earlier source or composing copy, and not necessarily copying errors on Kellner's part. This view is supported by Zoltán Szabó. The three manuscripts are in the Berlin State Museum and have been in the possession of the Bach-Gesellschaft since 1879, through the efforts of Alfred Dörffel. Two other eighteenth century manuscripts, both by unidentified copyists, have also survived.