COVID-19 Testing, Personal Protective Equipment, and Staffing Strategies Vary at Obstetrics Centers across the Country - Johnson, Jasmine D.; Melvin, Emilie; Srinivas, Sindhu K.; Louis, Judette M.; Hughes, Brenna; Han, Christina Shih-chi; Norton, Mary E.; Werner, Erika F. (American Journal of Perinatology, 2020)