<p>For anyone who loves the challenge of Su Doku but manages to solve them within minutes, you can now enjoy the extended mental workout and ultimate endurance test of a five grid interlinked system.</p>
<p> <strong>The ultimate lateral-thinking challenge.</strong> </p> <p>If you relish a serious mental workout, this collection of 100 brain teasers will demand your very best lateral thinking skills and mathematical rigour to solve. These puzzles will amuse and perplex in equal measure.</p>
<p>A compilation of 100 cryptic crosswords from The Sunday Times, one of the greatest crossword puzzle challenges. These brainteasers will test all cryptic crossword lovers to the limit!</p>
<p>Specially compiled to provide the most deadly Su Doku challenge, this is the only volume for Su Doku enthusiasts who need a puzzle that really tests their mettle.</p>