1. University of Washington School of Medicine, Seattle, Washington, USA
2. University of the Incarnate Word School of Osteopathic Medicine, San Antonio, Texas, USA
3. Albert S. Cook Library, Towson University, Towson, Maryland, USA
4. Welch Medical Library, Johns Hopkins University, Baltimore, Maryland, USA
5. Cochlear Center for Hearing and Public Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
6. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
7. Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.