1. a Analytical Research Department , Merck Research Laboratories Merck & Co., Inc. , P.O. Box 2000, Rahway, New Jersey, 07065-0914
2. b Chemical Engineering Research Department , Merck Research Laboratories Merck & Co., Inc. , P.O. Box 2000, Rahway, New Jersey, 07065-0914
3. c Developmental Laboratories , Merck Research Laboratories Merck & Co., Inc. Hertford Road , Hoddesdon, Hertfordshire, EN11, 9BU, England