Neb. Rev. Stat. § 43-104.16: Neb. Rev. Stat. § 43-104.16

In all cases involving the adoption of a minor child born out of wedlock, the agency or attorney representing the biological mother shall execute an affidavit stating that due diligence was used to identify and give actual or constructive notice to the biological father or possible biological fathers of the child and stating the methods used to attempt to identify and give actual or constructive notice to those persons or the reason why no attempts were made to identify and notify those persons. The affidavit shall be filed in the adoption proceeding prior to the hearing on the petition for adoption.