This coupon entitles barer to an additional 10% off any single "Artology" or "Writology" series books penned by "H.A. Calahan", "Drew Calahan" or "H.A. 'Drew' Calahan". Coupon must be redeemed by submission to the above named individual. This coupon valid for discount on one book, in one transaction. This coupon can not be combined with any other offers or promotions. Coupon has no real expiration date. Disregard "expiration date" printed.