1. a TSI Incorporated, 500 Cardigan Road, Box 3394, St. Paul, Minnesota, 55165, USA.
2. b Nihon Kagaku Kogyo Co., Ltd., 2-1, Shimizu, Suita, Osaka, Japan.
3. c National Institute of Industrial Health, 6-21-1, Nagao Tama-Ku, Kawasaki, Kanagawa, 213, Japan