I just added to the site the Slitherlink and Killer Sudoku books I wrote back in 2009, and which have been available on Amazon.com and Lulu.com for years but not previously as downloadable PDFs.

Both books have had some great reviews on Amazon.com, which you can click through to read if you wish from the books page.

The books are:

• Slitherlink: 100 Loop-the-Loop Puzzles and How to Solve Them
• Killer Sudoku: 100 easy to hard puzzles and how to solve them