Found in 2 comments on Hacker News
tzs · 2016-05-31 · Original thread
> Practice, and read about similar puzzles/problems. Track down reprints/scans of Martin Gardner's Mathematical Games and similar publications.

The entire set of the 15 books that collected his "Mathematical Games" columns from Scientific American are available in PDF form on a CD-ROM:

http://www.amazon.com/Martin-Gardners-Mathematical-Games-Gar...

tzs · 2012-10-10 · Original thread
The entire collection of the books that collected those columns is available on CD-ROM as PDFs: http://www.amazon.com/Martin-Gardners-Mathematical-Games-Gar...

Fresh book recommendations delivered straight to your inbox every Thursday.