Neb. Rev. Stat. §§ 10-607
Any city of the second class in the State of Nebraska which has heretofore voted and issued bonds to aid in the construction of any railroad or other work of internal improvement and which bonds or any part thereof still remain unpaid and are a legal liability against such city, and have been finally so determined by a court of competent jurisdiction, and bearing interest at ten percent per annum, is hereby authorized to issue coupon bonds at a rate of interest set by the governing body, to be substituted in place of and exchanged for such bonds heretofore issued, whenever such city can effect such substitution and exchange, which substitution and exchange shall not exceed dollar for dollar; Provided, such substitution and exchange shall have first been duly authorized by a majority vote of the people of said city at an election to be held for the purpose as provided in section 10-606.
Neb. Rev. Stat. §§ 10-607