Neb. Rev. Stat. §§ 10-407
The mayor and council of cities of the second class shall have the power to borrow money and pledge the property and credit of such city upon its negotiable bonds in an amount not to exceed one and eight-tenths percent of the taxable valuation of the taxable property within the limits of such city for the purpose of aiding in the building, erecting, constructing, or repairing and furnishing of a county courthouse, in addition to bonds already voted by the county, if authority for the issuance of such bonds has first been obtained by a majority vote of the qualified electors of such city voting on a proposition for such purpose at any general or special election. Such proposition shall be submitted to such electors in the manner provided by law for the submission of propositions to aid in the construction of railroads and other internal improvements. Such bonds shall be sold for not less than par and shall run not to exceed twenty years. The proposition to submit the issue of creating bonded indebtedness therein shall not be resubmitted on the same subject at an election within six months after such proposition has failed to pass.
Neb. Rev. Stat. §§ 10-407