READING ACTS: Apocalypse of Abraham. This is a good summary of this mysterious text. One important point not mentioned is that our only sources for it are medieval and later manuscripts in Slavonic. There does seem to be a respectable case, though, that it is a relatively early and Jewish composition. But Slavonic material is outside my expertise.
Incidentally, it is possible that Richard Bauckham has located a reference to the Apocalypse of Abraham by a late-antique, Latin-writing author. See his "The Inquiry of Abraham" in Old Testament Pseudepigrapha: More Noncanonical Scriptures, volume 1 (ed. Bauckham, Davila, and Panayotov; Eerdmans, 2013), pp. 59-63.
Presumably, the Apocalypse of Abraham was originally written in Greek and was translated into Slavonic. But none of the Greek text survives.
UPDATE: Bad link now fixed!