Difficult Sudoku Twelve Logic Puzzles (Vol 1)
Chapter 32: Two Difficult (DiffLev 10-11) Imponderably Puzzles (numbers 143-144)
- Step-by-step instructions for solving Puzzle 143, (85/144) Diff: 10/99.7989.6891
- Step-by-step instructions for solving Puzzle 144, (90/144) Diff: 11/996.4799.7994