1. Robert Wood Johnson Foundation Clinical Scholars, University of Michigan, Ann Arbor, Michigan, USA;
2. VA Center for Clinical Management Research, VA Ann Arbor Healthcare System, Ann Arbor, Michigan, USA;
3. Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, USA;
4. Department of Otolaryngology-Head and Neck Surgery, University of Cincinnati, Cincinnati, Ohio, USA;
5. A. Alfred Taubman Health Sciences Library, University of Michigan, Ann Arbor, Michigan, USA
6. Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA