Cologne: Wallraf-Richartz Museum, 1970-71. In two volumes, comprising the 4th revised edition and the 5th revised edition. Thick 4to. Text and images printed on a variety of paper stocks as well as acetate sheets. Each volume profusely illustrated. Publisher's bolt-bound quarter plexiglass and thick flexible vinyl wrappers, wear and warping, library label at foot of spine of 4th edition; library label and pocket mounted at rear of 4th edition; scattered light to moderate wear in each volume.