Neb. Rev. Stat. §§ 18-2524
Whenever an initiative petition bearing signatures equal in number to at least fifteen percent of the qualified electors of a municipality has been filed with the city clerk and verified pursuant to section 18-2518, it shall be the duty of the governing body of such municipality to consider passage of the measure contained in the petition, including an override of any veto, if necessary. If the governing body fails to pass the measure without amendment, including an override of any veto, if necessary, within thirty days from the date it received notification pursuant to section 18-2518, the city clerk shall cause the measure to be submitted to a vote of the people at the next regularly scheduled primary or general election held within the municipality. If the governing body desires to submit the measure to a vote of the people at a special election prior to the next regularly scheduled primary or general election held within the municipality, the governing body shall, by resolution, direct the city clerk to cause the measure to be submitted at a special election. Such resolution shall not be subject to referendum or limited referendum.
Neb. Rev. Stat. §§ 18-2524