Here I present a video with some interesting aspects about the study of Sudoku in general
https://www.youtube.com/watch?v=PkciX6Nx2Yk&list=PLI40n2bVm44Re6y-qxrE4BLiRXRTvz_vy&index=7
It is a software designed by me to understand what Sudokus are about.
Regards.