The practice of printing : letterpress and offset / Ralph W. Polk and Edwin W. Polk. Polk, Ralph W. (Ralph Weiss), 1890- Polk, Edwin W., joint author. Printing. Z244 .P76 1971 655 POP Includes bibliographical references and index. Peoria, Illinois : Chas. A. Bennett Co., c1971. c1971. 1971 Text xii, 328 p. : eng