Suguru puzzle book for Adults

The book contains 200 excellent Suguru puzzles at the level Very Hard.
50 puzzles 7x7 75 puzzles 9x975 puzzles 11x11 All riddles have only 1 solution. 2 puzzles per page. The font size is correct you will not have to strain your eyes when solving puzzles.High quality paper and print (all puzzles read well, easy to write with pen and pencil without worry of bleed-through).
Suguru, also known as Tectonics or Number Blocks, is a Japanese puzzle invented by Naoki Inaba. The goal is to fill a given rectangular grid with numbers, so that every designated area contains a sequence of non-repeating, consecutive numbers, starting from 1 and going up. Also, adjacent (touching) cells should not contain the same number, even diagonally.