JS BACH's original manuscript of the Cello Suites has not been found. The only manuscript reference from J.S. Bach is the Luth version of the Suite N°5 called Pieces pour la luth à Monsieur Schouster" BWV 995.
Fortunately, four copies from the 18th Century survived. We often refer to each facsimile with a letter or number:
I : By A. Magdalena Bach, first half of the 18th c.
II : By J. Peter Kellner, first half of the 18th c.
III: By 2 different authors, mid 18th c.
IV: By Author unknown, from the end of the 18th c.
Because these copies differ from each other, different interpretations of the slurs can be made. As of today, we count more than 90 editions of the cello suites. The choice of bowing and articulation is an endless debate for a cellist.
A-M BACH
First half of the 18th c.
J-P KELLNER
First half of the 18th c.
2 authors mid 18th c. Referred as Westphal copy
Author unknown, end of the 18th c.