Anthony J Leonardi, PhD, MS. (2022, January 23). Calling all GBD fans, your continued reinfection loyalty card. Nice one, @PeteUK7 https://t.co/AEMpdI5sr9 [Tweet]. @fitterhappierAJ. https://twitter.com/fitterhappierAJ/status/1485260239557509128

Russia’s Sputnik V Covid vaccine gaining acceptance in Europe. (2021, March 10). The Guardian. http://www.theguardian.com/world/2021/mar/10/russias-sputnik-v-covid-vaccine-gaining-acceptance-in-europe

Caption: "Figure 7.6 Physical Capital per Worker in the United States The value of the physical capital, measured by plant and equipment, used by the average worker in the U.S. economy has risen over the decades. The increase may have leveled off a bit in the 1970s and 1980s, which were, not coincidentally, times of slower-than-usual growth in worker productivity. We see a renewed increase in physical capital per worker in the late 1990s, followed by a flattening in the early 2000s. (Source: Center for International Comparisons of Production, Income and Prices, University of Pennsylvania)"

Coronavirus vaccination cards a target of scams—The Washington Post. (n.d.). Retrieved April 19, 2021, from https://www.washingtonpost.com/health/2021/04/18/scams-coronavirus-vaccination-cards/

COVID-19 and the Labor Market. (n.d.). IZA – Institute of Labor Economics. Retrieved October 10, 2020, from https://covid-19.iza.org/publications/dp13578/

Baker, S. R., Farrokhnia, R. A., Meyer, S., Pagel, M., & Yannelis, C. (2020). How Does Household Spending Respond to an Epidemic? Consumption During the 2020 COVID-19 Pandemic (Working Paper No. 26949; Working Paper Series). National Bureau of Economic Research. https://doi.org/10.3386/w26949