Establishing an ad hoc COVID-19 mortality surveillance during the first epidemic wave in Belgium, 1 March to 21 June 2020, Renard, Françoise, Scohy Aline, Van der Heyden Johan, Peeters Ilse, Dequeker Sara, Vandael Eline, Van Goethem Nina, Dubourg Dominique, De Viron Louise, Kongs Anne, et al. , Eurosurveillance, Feb-12-2021, Volume 26, Issue 48, (2021)