Okla. Stat. tit. 12, § 3005
The contents of an official record or of a document authorized to be recorded or filed and actually recorded or filed, including data in any form, if otherwise admissible, may be proved by copy, certified as correct in accordance with Section 902 of this Code or testified to be correct by a witness who has compared it with theoriginal. If a copy which complies with this section cannot be obtained by the exercise of reasonable diligence then other evidence of the contents may be given.
Laws 1978, c. 285, § 1005, eff. October 1, 1978.