1. Reversible Formation and Eradication of Colors by Irradiation at Low Temperatures. A Photochemical Memory Model
2. Industrial groups involved in photochromism: 1. National Cash Register Company, Polaroid Corporation, Xerox Corporation, American Cyanamide, Eastman Kodak (USA)… 2. Telefunken A.G., Kalle A.G., (West Germany)… 3. Fuji Photofilm, Toray Industries (Japan)… 4. Agfa Gevaert Company (Belgium)… 5. Compagnie St Gobain (France)…