Neb. Rev. Stat. § 76-219: Neb. Rev. Stat. § 76-219

If the instrument is executed and acknowledged or proved in any other state, territory or district of the United States, it must be executed and acknowledged or proved either according to the laws of such state, territory or district or in accordance with the law of this state, and if acknowledged out of this state it must be before some court of record or clerk or officer holding the seal thereof, or before some commissioner to take the acknowledgment of deeds, appointed by the Governor of this state, or before some notary public.