1. a Dainippon Ink & Chemicals, Inc. , 4472-1, Komuro, Inamachi, Kitaadachigun, Saitama , Japan
2. b Merck Japan Ltd. , 4084, Nakatsu, Aikawa-machi, Aiko-gun, Kanagawa , Japan
3. c Merck KGaA , Frankfurter Str. 250, 64293 , Darmstadt , Germany
4. d Chisso Corporation , 7-3, Marunouchi 2-chome, Chiyoda-ku, Tokyo , Japan