“…More generally, for interesting works applying spatial and spatio-temporal model to COVID-19 data, we can refer to Aràndiga et al, 2020 , Bertuzzo et al, 2020 , Giuliani et al, 2020 , Mollalo et al, 2020 , Kang et al, 2020 , Bartolucci and Farcomeni, 2021 , Lee et al, 2021 , Sahu and Böhning, 2021 , Vitale et al, 2021 . For the application of a robust non linear regression model to the same data, see Girardi et al (2020) .…”