Sign In [SIGN-4-009P]
Example
Sign In Puzzle Archive 
Similar Puzzle Books
1000 Math Logic Puzzles – Collection I
US, CA; UK, DE, FR, ES, IT, other
This book has ten different math logic puzzles: Kakuro, From 1 to X, Doppelblock, Futoshiki, Sign In, Digital Battleships, Index Sums, Tenner Grid, Number Cross, and Grades.
