Neb. Rev. Stat. § 77-27,226

Whenever, at least forty-five days prior to any county or state election, the registered voters of the county, equal in number to ten percent of the votes cast at the last preceding county election, petition the county board to submit the question of imposing a license or occupation tax under section 77-27,223 , the county board shall submit the question at the next primary, general, or special election.