It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
What Can I Do if a review is not available for my book?
Sometimes it is difficult to find a book review -- the book may be very old, very new, not widely distributed. In addition, many more books are published than are reviewed. If that happens, you can stilI make a reasonable, responsible purchasing decision.
Consider the reputation of the author
Consider the reputation of the publisher
Unless the book is the first book the author has published, return to the standard reviewing sources you have already checked. This time search for the author and do not include the title you are looking for. Read reviews of the author's other books. If they are overall positive, it is reasonable to purchase the new book by this author.
Particularly if the author has not yet published widely, biographical material about the author, and his/her background, can also help you decide. Try biographical sources such as those found at: https://www.lib.ecu.edu/databases/tag/biography
The quality and reputation of the publisher can be determined in a variety of ways.
Check the publisher's web page (which often contains their current catalog of offerings) to see what kinds of books they publish and how they appear (are they cheaply constructed? Are the covers and illustrations generally well done?
Search reviewing sources you have already searched but confine your search to publisher -- are there many books published by that publisher that are reviewed? Overall, are they positive reviews or do the reviews note concerns about the quality of the books (do the reviews note that there are errors or inaccuracies?)
Check library catalogs to see whether books published by this publisher are fairly widely held in libraries. You can use the WorldCat database to do this.