Publication access
On the JAMA article page, find the August 13, 2020 online comment with this title by Charles Courtemanche, Benjamin Sommers, and Aaron Yelowitz. The main JAMA research article on that page is a different work.
Citation
Charles Courtemanche, Benjamin D. Sommers, and Aaron Yelowitz. "Evidence on U.S. School Closures and COVID-19 Spread Is Inconclusive." Online comment on "Association Between Statewide School Closure and COVID-19 Incidence and Mortality in the US," JAMA, August 13, 2020.