Only one inscription pertaining to the reign of Nabû-šumu-libūr is known today.
A short Akkadian inscription on a duck weight found at Nimrud states that this object weighed thirty minas and belonged to Nabû-šumu-libūr, "king of the world."
Access the composite text of Nabû-šumu-libūr 1 [/ribo/babylon2/Q006276/].
Source
Bibliography
Alexa Bartelmus
Alexa Bartelmus, 'Inscriptions', RIBo, Babylon 2: The Inscriptions of the Second Dynasty of Isin, The RIBo Project, a sub-project of MOCCI, 2024 [http://oracc.museum.upenn.edu/ribo/babylon2/Rulers/Nabu-shumu-libur/Inscriptions/]