The best way to find criticisms may be to find books on the play and/or playwright.
Start in the ONU library catalog. There will be physical books and ebooks available. If you can't find what you need there, search in OhioLink.
Depending on the play/playwright you may need to search for the title or the playwright.
Finding a clickable subject or author name will help narrow the search.
Google may be your best friend for finding modern production history.
Wikipedia usually has a production history or selected production history. You can take this and build on it. There also may be references you can use.
Use these indexes to find reviews of productions: