Okla. Stat. tit. 63 § 4042
Service Oklahoma may deny any application for license, or suspend or revoke a license issued or impose a fine, only after a hearing of which the applicant, or licensee affected, shall be given at least ten (10) days' written notice specifying the reason for denying the applicant a license, or, in the case of a revocation or suspension or imposition of a fine, the offenses of which the licensee is charged. Such notices may be served as provided by law for the service of notices, or by mailing a copy by registered mail to the last-known residence or business address of such applicant or licensee. The hearing on such charges shall be at such time and place as Service Oklahoma may prescribe and the aforementioned notice shall further specify the time and place. Service Oklahoma shall have the power to compel the production of all records, papers and other documents which may be deemed relevant to the proceeding bearing upon the complaints. Service Oklahoma shall have the power to subpoena and bring before it any person, or take testimony of any such person by deposition, with the same fees and mileage and in the same manner as prescribed in proceedings before courts of the state in civil cases. Any party to such hearing shall have the right to the attendance of witnesses in his behalf upon designating to Service Oklahoma the person or persons sought to be subpoenaed.
Okla. Stat. tit. 63, § 4042