Walther, George R. Upside-down marketing : turning your ex-customers into your best customers / George R. Walther. - New York : McGraw-Hill., 1994. - xix, 209 pages : illustrations ; 22 cm. Includes index Includes index. ISBN: 9780070680487 0070680485 Subjects--Topical Terms: Customer services--Management. Marketing--Management. Sales management.