CoinGecko currently has the How to DeFi and How to Bitcoin books published. These books are offered for sale in the CoinGecko Store as ebooks. Once you made the purchase, you will be emailed the PDF, ePub, and Mobi version of the ebooks.
If you would like to buy a physical, hardcopy version of the book, you can do so by buying it on Amazon. Here are the links to Amazon for you to buy: