These library databases are designed solely to provide access to book reviews:
Nexis Uni (formerly Lexis Nexis) houses hundreds of newspapers, and might include book reviews and author interviews.
This tutorial explains how to find Critical Reviews in Lexis Nexis Academic:
Literature Resource Center allows you to limit your search to Reviews & News. Search for the work and author you're researching as keywords, then click on the Reviews & News tab.
These general subject databases contain academic journal articles, newspaper articles, magazine articles, and trade journals that might have reviews of more modern literary works or works of criticism.
In Academic Search Premier, you can limit your search to Book Review under Document Type on the main Advanced Search page. Search for your title or author.
Also try these databases for reviews of books in academic journals: