VERY IMPORTANT TIP: Search Book Review Index before tackling newspaper indexes to find out the EXACT months/years where the majority of newspaper reviews are likely to appear. You may need those dates to sift through newspaper search results.
Although over time the number of newspapers containing large numbers of book reviews has diminished greatly, newspapers are still excellent sources of book reviews, and a way that you can sometimes get a geographical perspective on a book. In the U.S., the New York Times, Los Angeles Times and the Washington Post still review large numbers of books.
ACCESS World News , Factiva, Nexis Uni, and Newspaper Source will each help you find additional book reviews in newspapers from all over the world. Follow the instructions for searching them very carefully. There is nothing intuitive about searching for book reviews in these databases!