Signs of the Times : : 1: Trade Signs and Symbols of the Nineteenth Century ; 2: Poster and Billboard Art of the Nineteenth and Early Twentieth Centuries ; 3: Paintings by Twelve Contemporary Pop Artists (Exhibition Catalog and Guide, Des Moines-Iowa, des Moines Art Center, 06.12.1963 - 19.01.1964 ; Andover-Mass., Addison Gallery of American Art, 15.02 - 22.03.1964) / / Foreword by Thomas S. Tibbs.boek