Thank you very much for all your recommendations. In the beginning I wanted to make this website in Wordpress but the autor told me that he wants joomla. He does not want the book to be downloaded. He wants that people order the book and pay for it in his website. Customers must pay by paypal or credit card and he will take care of sending the purchased books by mail.
Maybe in the future he wants to sell more books. For now it is just one.