There may have been a common or shared cultural identity among the Early Dynastic Sumerian city-states, despite their political fragmentation. This notion was expressed by the terms "kalam" or "ki-engir". Numerous texts and cylinder seals seem to indicate the existence of a league or amphictyony of Sumerian city-states. For example, clay tablets from Ur bear cylinder seal impressions with signs representing other cities. Similar impressions have also been found at Jemdet Nasr, Uruk, and Susa. Some impressions show exactly the same list of cities. It has been suggested that this represented a system in which specific cities were associated with delivering offerings to the major Sumerian temples, similar to the "bala" system of the Ur III period.