 The Oriental Institute of the University of Chicago recently completed a 21-volume dictionary of the Akkadian language, which is available commercially and online.The following table summarises the dialects of Akkadian identified with certainty so far.Some researchers (such as W. Sommerfeld 2003) believe that the Old Akkadian variant used in the older texts is not an ancestor of the later Assyrian and Babylonian dialects, but rather a separate dialect that was replaced by these two dialects and which died out early.