70 ILCS 2805/6

All ordinances, orders and resolutions, and the date of publication thereof, may be proved by the certificate of the clerk under the seal of the corporation, and when printed in book or pamphlet form, and purporting to be published by the board of trustees, such book or pamphlet shall be received as evidence of the passage and legal publication of such ordinances, orders and resolutions, as of the dates mentioned in such book or pamphlet in all courts and places without further proof.