• A citator is a research tool that allows one to look up a specific citation (to a case, a statute, etc.) to discover other resources that cite it.  This is used, for example, to verify the validity of a case (is it still good law? --- or, has it been subsequently overturned, or reversed on appeal?) or to find additional cases or other materials on the same topic.
  
  
• While some citators are available in paper format, the online versions are more up-to-date and more efficient to use.

You can:

--determine the validity of a case (has it been reversed on appeal?  been overruled?  been treated negatively by a subsequent court?)

--discover the history of a case (prior and subsequent)

--find parallel citations

--locate other cases that have cited your case (and are likely to deal with a similar issue)

--locate secondary sources that have cited your case & address your topic

You can -

--discover the history of a statute (Has it been amended? Reversed? Is there pending legislation?)

--locate cases that have cited the statute

--learn how citing cases have interpreted the statute

--discover secondary sources that cite the statute & address your topic

See Shepard's Statute Reports

Shepard's Citations (via LexisNexis)

• Shepard's Citations via Lexis.com (law school password required)
  See Shepard's Product Guide
• Shepard's Citations via Lexis Advance (law school password required)
  Start your Shepard's request with shep:
• Shepard's Citations via LexisNexis Academic (available to all at UB)
  Click on "US Legal" in the left frame; then click on "Shepard's Citations".
  NOTE:only CASES can be shepardized on this platform

​KeyCite (via Westlaw)

• KeyCite via Westlaw (law school password required)
• KeyCite via WestlawNext (law school password required)
  Type kc or keycite followed by a citation, e.g., kc 93 sct 1817 or keycite 93 sct 1817, in the text box at the top of the page and click Search.

BCite

• Bloomberg Law ’s legal citation tool (under development?)