To purchase a PDF-version of the e-book on Amazon, please follow these steps: 1 Open Amazon and enter the name or keyword of the book you want to buy in the search box. 2. The system will list all the books related to the search term. 3 On the book details page, click the "Buy" button to enter the Amazon shopping cart. 4. Choose the book you want to buy in the shopping cart and click the "Settlement" button. 5 On the settlement page, choose the "Continue" option and then choose "Use Amazon Points" or "Other Dollars" to settle the settlement. 6. Choose the payment method and enter the payment information. 7. Confirm the order information and wait for Amazon to deliver the goods. Please note that if you're using Amazon's Kindle or other digital readers, you may need to convert the PDF-file into a readable format. Please make sure to use the free conversion service provided by Amazon and comply with the copyright laws after conversion.