1. University of California Irvine, California.
2. University of Pittsburgh Medical Center, Pennsylvania.
3. University of Texas Southwestern Medical Center, Dallas, Texas.
4. Case Western Reserve University, Cleveland, Ohio.
5. Cleveland Clinic, Cleveland, Ohio.
6. Mayo Clinic, Department of Urology, Rochester, Minnesota.
7. Columbia University Medical Center, New York, New York.
8. University of Minho, school of Health Science, Braga, Portugal.
9. East Surrey Hospital, Redhill, United Kingdom.
10. Mayo Clinic, Department of Urology, Phoenix, Arizona.