Neb. Rev. Stat. § 43-104.23

(1) The court shall enter a decree finalizing the adoption of the child if, after viewing the evidence submitted to support a petition for adoption, the court determines that: (a) No biological father can be identified; (b) No identified father can be notified without likely threat to the safety of the biological mother or the child; or (c) That there has been due diligence and substantial compliance with sections 43-104.08 to 43-104.16 and that no biological father has timely filed under section 43-104.02 or 43-104.05 . (2) Subject to the disposition of an appeal, upon the expiration of thirty days after a decree is issued under this section, the decree shall not be reversed, vacated, or modified on the basis of fraud, misrepresentation, or failure to provide notice under sections 43-104.12 to 43-104.14 .