The statements and opinion of the chief fiscal officer contained in such financial report with respect to expenses and revenues may be based upon statements or data contained in, and appropriate schedules and summaries may be incorporated by reference to, the final report of the head of the department or agency of the city having jurisdiction over the project involved or, as appropriate, certificates of any registered engineer, registered architect, certified public accountant or other qualified expert who shall have been engaged to compile the relevant data, in which case such final report or certificates shall be attached to the report of the chief fiscal officer.
53 P.S. § 15908