1. Department of Epidemiology and Biostatistics, The University of Arizona, Tucson, Arizona, USA.
2. College of Pharmacy, Mercer University, Atlanta, Georgia, USA.
3. Department of Community, Environment and Policy, The University of Arizona, Tucson, Arizona, USA.
4. Arizona Health Sciences Library, The University of Arizona, Tucson, Arizona, USA.
5. U.S. Department of Agriculture, Washington, District of Columbia, USA.