Typically, researchers are looking for appellate court opinions that establish and clarify the law in the jurisdiction.  These opinions are readily provided by the Oklahoma courts and various commercial vendors.  Researchers without access to a subscription research service can search the court's website for opinions or use Google Scholar.  

The first step to locate cases is to develop a list of search terms by analyzing the problem.  Researchers should list key facts, issues, areas of law, and jurisdiction.  Researchers can use this list of search terms to search the appropriate case law database for the jurisdiction in question.  Once a list of cases is retrieved, researchers should review the cases to see if they are relevant to their research problem.  

Researchers also need to verify the validity of each case.  The holdings or conclusions of law of cases can be overturned or questioned by a later court opinion.  Subscription research services provide citators for this purpose.  If a researcher has a list of cases to be checked by a citator, the research can contact their local law library who may provide that service.  Without using a citator, researchers should locate all relevant cases by following citations to other cases and trying different keyword searches.

Law libraries may provide free access to public or academic versions of Westlaw and Lexis.  Research should contact their local law library for assistance.