Neb. Rev. Stat. § 52-601.01: Neb. Rev. Stat. § 52-601.01

A person who shall perform work or labor, or exert care or diligence, or who shall advance money or material upon personal property under a contract, expressed or implied, and who holds such property for a period of ninety days, may dispose of the property by sale or other manner. Such disposition shall not occur until thirty days after the mailing of a written notice of the intended disposition by certified mail, return receipt requested, to the last-known address of the owner of the personal property to be disposed of, and to any lien or security interest holder of record.