Some book review sources are not appropriate for scholarly work. Avoid reviews in popular magazines such as Choice, Library Journal, Publisher's Weekly, Booklist, etc. Reviews in these kinds of publications are not scholarly reviews.
Aim to collect book reviews from scholarly journals.
In addition, book reviews in publications like The Times Literary Supplement, London Review of Books and The New York Review of Books may be acceptable as they are often written by scholars.
Search the history databases and Book Review Digest simultaneously to find book reviews:
Historical Abstracts covers reviews in history journals for non-North American history. America: History & Life is the best source for scholarly book reviews for topics in North American history. Add Academic Search Complete, which is a good general database covering scholarly journals in many different disciplines, and the book review database Book Review Digest, to get the best search possible. You could also consider adding other subject databases if appropriate, for example the Political Science Complete database.
1. After clicking on a link to get to an EBSCO database, click on the "Choose Databases" link to select the databases you want to search simultaneously:
2. Type in the: title of the book:
3. Scroll down and select "Book Review" from the Document Type list:
Use the 
button to find the journal online, in Seymour Library, or to request it via interlibrary loan.