You can find cases on the Individuals with Disabilities Education Act of 1991 (IDEA) in various places. Here are a few options:

1. U.S. Department of Education Office of Special Education Programs (OSEP) Website: The OSEP website maintains a database of significant IDEA-related legal decisions issued by federal and state courts. The database is searchable by keyword, type of decision, and other criteria. You can access the OSEP Legal Decisions page here: https://sites.ed.gov/idea/osep-legal-decisions/

2. United States Courts Website: The United States Courts website provides access to federal court opinions and orders, including those related to IDEA. You can search the opinions and orders by keyword, court, and other criteria. You can access the United States Courts website here: https://www.uscourts.gov/

3. Westlaw or LexisNexis: Westlaw and LexisNexis are subscription-based legal research services that provide access to a variety of legal materials, including court decisions related to IDEA. You can search for cases using keywords, names, and other criteria. Both services offer free trials if you don't have a subscription. You can access Westlaw here: https://www.westlaw.com/ and LexisNexis here: https://www.lexisnexis.com/en-us/gateway.page.

4. Google Scholar: Google Scholar is a free search engine that provides access to scholarly literature, including legal opinions. You can search for cases related to IDEA using keywords and other criteria. You can access Google Scholar here: https://scholar.google.com/.

Note: It's important to remember that while reviewing case documents can be helpful, interpreting case law can be complicated. Consider consulting with an attorney or trained disability advocate when reviewing legal decisions.