There are lists of probable predatory research journal publishers and stand-alone journals. How can we know that a book publisher (whether in print or e-book) is a probable 'predatory'?
Beall's List is "the" list that you need to check out. This link is to the Predatory Publishers but he also has a list of stand alone predatory journals, and a blog where the issues are discussed.
Thank you Prof. Robert for your answer. However, we are also curious if there is also a list of probable 'predatory' publishers of books / e-books (not only journals) in the web or in any particular country. There are some offers of e-book publishing in the internet but we don't have a way to determine if they are 'legitimate' or 'predatory'.
Prof. Castillo - do look at the website of the publisher and see if they are on Beall's List and then avoid them or any company that 'looks' like them, as many of these are publishing books as well as the journals. If they publishing only books, look at their claims and they sound too good, they probably are predatory. Find out some of the books they published and look up the email of the authors and find out from them if the publishing process was good and worth it. But in general, if a book publisher wants you to pay for publishing, they need to provide quality services to you. Major book companies do this for free and then make money on the book sales.