This Griddlers book now comes with a bonus. When you order the book "Griddlers Logic Puzzles: Black and White (Volume 16)" you will get either a PDF version of the book for free or a 4 months' subscription.
How do you receive the bonus? It's easy as 1..2..3!
1. Buy Griddlers BW16 book on Amazon.com
2. Send a copy of your invoice or a photo of you with the book to email@example.com
3. Send us the secret code printed in the book - there are several codes hidden in each book, we will tell you how to find them
This offer is limited to purchaces made before 30th November 2015.