Edit. George Allen & Unwin Ltd., 1957 London. 8ºM (22x15cm) 672 págs. Tela editorial con sobrecubierta. Cubierta deslucida, algo rozada con lomo soleado. Muy buen estado general. «A remarkable book… It is impossible in this brief sketch to convey an adequate impression of this brilliant book… Such a book, surveying things as they are in the light of what they must become, was needed.» Lord Haldane in The Observer.