Scherpe Verlag, Krefeld, 1961. 87 pages + colophon. 4to (27,5 x 18,5 cm). Blue cloth binding, black spine label gilt. No jacket. 9 plates in colour and many diagrams. Translated from the Spanish by Heinz Nieth. Designed, edited and with a foreword by Hermann Zapf, and printed in his Optima-Antiqua type. Text in German. (Hermann Zapf and his Design Philosophy page 116).