1. Department of Mathematics, University of Pisa, 56127 Pisa, Italy
2. Department of Mathematics and Physics, University of Campania “L. Vanvitelli”, 81100 Caserta, Italy
3. Department of Physics and Astronomy, University of Padova “G. Galilei”, 35122 Padova, Italy
4. Department of Mathematics, University of Salerno, 84081 Salerno, Italy
5. OpenSci.World, Montreal, QC H4R 2R9, Canada
6. Department of Physics and Chemistry—Emilio Segrè, University of Palermo, 90128 Palermo, Italy