1. Andros Men's Health Institutes; Arnhem The Netherlands
2. Center for Reproductive Medicine and Andrology; Martin Luther University Halle-Wittenberg; Halle Germany
3. Southwestern Medical Center; University of Texas; Dallas TX USA
4. Sexual Medicine and Andrology Unit; Department of Experimental and Clinical Biomedical Sciences; University of Florence; Florence Italy
5. University of Manchester; Manchester UK
6. Erasmus Medical Center; Rotterdam The Netherlands
7. Barnsley Hospital NHS Foundation Trust; Barnsley UK
8. Private Practice of Urology/Andrology; Hamburg Germany
9. Holly Cottage Clinic; Lichfield Staffordshire UK
10. New England Research Institutes, Inc.; Watertown MA USA
11. Carlos Haya University Hospital; Málaga Spain
12. VU Medical Center; Amsterdam The Netherlands
13. Baylor College of Medicine; St. Luke's Episcopal Hospital; Houston TX USA