Complex sentence: Bartholomew carefully notes the sources for the material included, although, at present, it is sometimes impossible to identify or locate some of them, but his annotations give a good idea of the wide variety of works available to a medieval scholar.
Split into simpler sentences: Bartholomew carefully notes the sources for the material included, although, at present, it is sometimes impossible to identify or locate some of them. His annotations give a good idea of the wide variety of works available to a medieval scholar.