Well, people around the world tend to produce more books to sell until the internet is introduced to the people. Although, search engines before is not that yet common but as the time pass by people tend to put their books in the internet and start monetizing it by making blogs. And in the present, technology is getting advanced, meaning more information you can obtain in the internet than in the books. It's just up to you how you will use the internet nowadays to advance your research and gambling books are just small numbers compared to the whole world information.
Therefore, when it comes to searching for books about gambling, it is very easy to find and even paid ones can be accessed for free (even though such actions do not respect the author's work). Everything can be accessed easily and you don't have to bother visiting bookstores anymore. The internet provides everything you need so make the most of it. Even the list of gambling books, which we haven't fully read until the last page, requires motivation to increase reading literacy.
