1. Merck & Co Inc , Kenilworth, New Jersey , USA
2. Organon & Co Inc , Jersey City, New Jersey , USA
3. Centre for Reproductive Medicine and Andrology, University Hospital Münster , Münster , Germany
4. Centre for Reproductive Medicine and Andrology, University Hospital Halle , Halle , Germany
5. Lundquist Research Institute, David Geffen School of Medicine at UCLA , Torrance, California , USA