The downfall of the Akkadian Empire

What types of evidence do scholars employ to understand the downfall of the Akkadian Empire? Further to just the information in the textbooks, I used more resources. Regarding types of evidence, scholars employ to understand the downfall of the Akkadian Empire can include bronze heads, ancient artefacts, maps and also styles. An example is the stele of naram-Sin.It also noted that the Gutians attacked and the Akkadians ended the empire. Scholars also noted the Akkadian empire suffered a drought which could have aided in its downfall of the Akkadian Empire.