To find reviews in Discovery Search, search for the title of a film. On the results page, select ‘Reviews’ under the Format heading.
This database, which cross searches the American Film Institute Catalog (AFI), Film Index International (FII) and FIAF International Index to Film Periodicals Database, also contains reviews from a number of different sources.
To find reviews, search for the title of the film you're interested in. On the results page, select 'Review' under the 'Document Type' heading.