Complex sentence: The occurrence of signs incised on the bottom of several vessels, particularly on those at Turdaş (Hunedoara County), often regarded as the potter's mark, more recently have been considered by some researchers as early attempts at recording dates graphically.
Split into simpler sentences: The occurrence of signs incised on the bottom of several vessels, particularly on those at Turdaş (Hunedoara County), have often been regarded as the potter's mark. More recently they have been considered by some researchers as early attempts at recording dates graphically.