Neb. Rev. Stat. § 70-505
In order to consummate and complete the sale, lease, or transfer of any electric light and power plant, distribution system, or transmission lines by any city, village, or public electric light and power district of this state, to any private person, firm, association, or corporation, there shall be filed in the office of the Nebraska Power Review Board of this state, prior to any delivery or change of possession, control, or management under such sale, lease, or transfer, true and exact duplicate signed copies of all agreements, conveyances, contracts, franchises, deeds, leases, bills of sale, and other instruments, under which such sale, lease, or transfer is to be made. Said instruments shall be certified to under the oath of the executive or presiding officers of the seller and purchaser, respectively, as such true and exact duplicates.
Neb. Rev. Stat. § 70-505