Uhadaika. Skladni Sudoku (Hard Sudoku) is a special edition of difficult sudoku puzzles for those who have outgrown easy ones. Sudoku is the game that has captured the minds of millions: you fill a square grid with digits so that none repeats in any row, column or block. Hard puzzles demand concentration and are an excellent workout for logical thinking. The publisher is Sobol-Press Publishing House. It is a special edition, published in Russian. The issues archive on journals.ua holds 6 issues from 2013, the latest dated June. You can buy Uhadaika. Skladni Sudoku online as a single issue, fro…