Neb. Rev. Stat. §§ 19-1304
All funds received by the city treasurer or village treasurer, by donation or by tax levy, as provided in sections 19-1301 to 19-1304, shall, as they accumulate, be immediately invested by such treasurer, with the written approval of the city council or village board of trustees, in the manner provided in section 77-2341. Whenever investments of such sinking fund or funds are made, the nature and character of the same shall be reported to the city council or village board of trustees, and such investment report shall be made a matter of record by the city clerk or village clerk in the proceedings of such city council or village board of trustees. The sinking fund, or sinking funds, accumulated under sections 19-1301 to 19-1304, shall constitute a special fund, or funds, for the purpose or purposes for which such fund or funds were authorized and shall not be used for any other purpose unless authorized by sixty percent of the qualified electors of such municipality voting at a general election favoring such change in the use of such sinking fund or sinking funds. The question of the change in the use of such sinking fund or sinking funds, when it shall fail to carry, shall not be resubmitted in substance for a period of one year from and after the date of such election.
Neb. Rev. Stat. §§ 19-1304