1. National Jewish Health, Denver, CO, USA
2. Alpert Medical School of Brown University/E. P. Bradley Hospital, Sleep for Science Research Lab, Providence, RI, USA
3. Indiana University School of Medicine, Indianapolis, IN, USA
4. Harvard Medical School, Boston, MA, USA
5. NYU Grossman School of Medicine, New York, NY, USA
6. University of Minnesota, Minneapolis, MN, USA
7. Loyola University Maryland, Baltimore, MD, USA