Complex sentence: The preferred assignment appears to be that the smaller fragment be designated as C2a: as early as 1994, a well known textbook recommended that the larger fragment of C2 should be designated C2b.
Split into simpler sentences: The preferred assignment appears to be that the smaller fragment be designated as C2a. As early as 1994,a well known textbook recommended that the larger fragment of C2 should be designated C2b.