1. Abadie A, Diamond A, Hainmueller J (2010) Synthetic control methods for comparative case studies: estimating the effect of California’s tobacco control program. J Am Stat Assoc 105(490):493–505
2. Abouk R and Heydari B (2020). “The immediate effect of COVID-19 policies on social distancing behavior in the United States.” Retrieved from SSRN: https://ssrn.com/abstract=3571421. Accessed 1 May 2021
3. Ahammer A, Halla M, Lackner M (2020) “Mass gatherings contributed to early COVID-19 mortality: evidence from US sports,” Economics working papers 2020–13, Department of Economics, Johannes Kepler University Linz, Austria
4. Baldwin SL, McNamara A, Linton C. Washington, D.C., locks down as inauguration events kick off. January 17, 2021. CBS News. https://www.cbsnews.com/live-updates/joe-biden-inauguration-washington-dc-lockdown/. Accessed 1 May 2021
5. Balsamo M (2021) Discovery of pipe bombs in DC obscured by riot at Capitol. January 11, 2021. The Associated Press. https://apnews.com/article/donald-trump-joe-biden-inaugurations-capitol-siege-8828a6a920198d0ea1ee0c73a49d8847. Accessed 1 May 2021