Neb. Rev. Stat. § 23-189

A county ordinance may be proved by the certificate of the county clerk under the seal of the county. The adoption and publication of the ordinance shall be sufficiently proved by a certificate under the seal of the county, from the county clerk, showing (1) that such ordinance was adopted and (2) when and in what paper the ordinance was published or when, by whom, and where the ordinance was posted.