When you mention a book in a post or comment, with just a little bit more effort you can make it more convenient for a reader who might be interested in buying the book to find it and, at the same time, generate some revenue to support hosting the Ratburger site or line your own pocket.
Suppose you should mention my own classic and highly collectible 1989 book, The Autodesk File. Note that the title of the book is in italic type (as book titles should be; magazine articles are in roman type surrounded by quotes), and that it has a link which, when clicked, takes you to the page on Amazon.com where you can empty your bank account buying a used copy. Here’s how I did that, and how you can too.
First, you need the International Standard Book Number (ISBN) for the book. If you have the book at hand, you’ll usually find it on the book’s copyright page and often the back cover. This is a 13 or, for older books, 10 character code which looks like 978-0-934035-63-7 or 0-934035-63-6. The punctuation is irrelevant, and may be ignored. The last character of a 10 character ISBN may be the letter “X”. If you don’t have a copy of the book, you can look it up on Amazon.com, which will give you, under “Product Details”, the ISBN-13 of the book, usually in the form 978-0934035637.
Now that you have the ISBN, go to the Fourmilab ISBNquest Web page. Enter the ISBN in the field with that name and press “Query”. You’ll get back a page with lots of information including, in the “Book Information from Amazon.com” section near the bottom, a link to the book’s page on Amazon, which will look something like “https://www.amazon.com/dp/0934035636/?tag=fourmilabwwwfour”. For convenience, this link is “hot”, so you can click it to display the page or use your browser’s “copy link address” feature to copy it to the clipboard. Now simply apply that link to the book’s title in your post or comment, and the title will take those who click it to the Amazon page for the book.
The “tag=fourmilabwwwfour” field in the link causes purchases made through the link (and subsequent purchases in the same session) to be paid a commission to Fourmilab’s Amazon Associates account, which is used to (partially) defray the costs of hosting Ratburger.org, which are commingled with those for Fourmilab.ch. If you have your own Amazon Associates account, or know the account tag for a business or worthy cause you wish to support, fill its tag in the “Amazon associate tag” field in the ISBNquest request form and it will be used instead. See the description in the ISBNquest page for details of the request form fields and results from a query.
(If you’re interested in reading The Autodesk File, don’t waste your money on a decades-old out of print copy. The current Fifth Edition, with more than twice the amount of material, is available on the Web for free.)