To search directly in the newspaper databases, input the name of your film in quotation marks, i.e. "The Magnificent Yankee" and review. You will likely need to limit your search results by date to the year of the film's release.
U.S. Newsstream features newspapers, newswires, blogs, and news sites dating back to 1980. Some titles include: Los Angeles Times, Chicago Tribune, The Washington Post, and The Wall Street Journal.
Performing Arts Periodicals Database (formerly International Index) provides indexing, abstracts and full text journals on dance, drama, theater, stagecraft, musical theater and performance art.
These freely available websites bring together reviews published in a variety of established and not-so-established online sources. Choose your reviews carefully, and try to learn as much as possible about the source that published them.
Movie Review Query Engine (MRQE)