Temporal rise in the proportion of younger adults and older adolescents among coronavirus disease (COVID-19) cases following the introduction of physical distancing measures, Germany, March to April 2020
Goldstein, Edward and Lipsitch, Marc, Eurosurveillance, 25, 2000596 (2020), https://doi.org/10.2807/1560-7917.ES.2020.25.17.2000596