[\'Golgi Cenci Foundation, Corso San Martino 10, 20081 Abbiategrasso, Italy.\', \'IRCSS-INRCA National Institute of Health & Science on Ageing, Centre for Socio-Economic Research on Ageing, 60124 Ancona, Italy.\']
Loneliness and Social Engagement in Older Adults Based in Lombardy during the COVID-19 Lockdown: The Long-Term Effects of a Course on Social Networking Sites Use.