• https://iris.uniupo.it/handle/11579/199666
• https://iris.uniupo.it/handle/11579/221562
• https://iris.uniupo.it/handle/11579/180002
• https://iris.uniupo.it/handle/11579/167662
• https://iris.uniupo.it/handle/11579/175942