Haber, N. A., Clarke-Deelder, E., Feller, A., Smith, E. R., Salomon, J. A., MacCormack-Gelles, B., …Stuart, E. A. (2022). Problems with evidence assessment in COVID-19 health policy impact evaluation: a systematic review of study design and evidence strength. BMJ Open, 12(1), https://doi.org/10.1136/bmjopen-2021-053820