Neb. Rev. Stat. § 25-1293: Neb. Rev. Stat. § 25-1293

The public seal of the state or county affixed to a copy of a written law or other public writing, is also admissible as evidence of such law or writing respectively; the unwritten law of any other state or government may be proved as fact by parol evidence, and also by the books of reports of cases adjudged in their courts.