I participate in the Amazon Services LLC Associates Program, an affiliate advertising program. So, when I link to a book or other product on Amazon.com and you buy the product by clicking on that link, I will receive a small percentage of the cost in return.
I never endorse any content based on compensation and the affiliate program will never influence what I share on my site. Basically, I was already recommending the products on Amazon.com so I decided to use links to help pay for the costs of hosting my website, which helps me keep my content free for you.