Neb. Rev. Stat. §§ 23-3515
Any two or more adjoining counties having a combined population of thirty-six hundred inhabitants or more or having a combined taxable value of the taxable property of twenty-eight million six hundred thousand dollars or more may, upon resolution of the county board of each county, issue their joint bonds in the amount, for the purposes, and upon the conditions provided in section 23-3501. No bonds shall be issued until the question of their issuance has been submitted to the voters of each county at a general election or at a special election called for such purpose. The issuance of such bonds shall be approved by a majority vote of the electors voting on such question in each county, which election may be called either by resolution of the county boards or upon a petition submitted to the county boards calling for the same signed by the legal voters of each county equal in number to ten percent of the number of votes cast in each county for the office of Governor at the last general election.
Neb. Rev. Stat. §§ 23-3515