1. S. H. Hasan:
Research Laboratories of Schering AG, Müllerstrasse, Berlin, Germany
2. W. Elger:
Research Laboratories of Schering AG, Müllerstrasse, Berlin, Germany
3. S. I. Ahmad:
Pharmacology Department, Faculty of Pharmacy, University of Karachi, Karachi, Pakistan
4. F. Neumann:
Clinical Research III, Berlin 65, Germany