Open your document in a word processor, and then add a new footnote to the document or a new entry to its works cited page.
Type the names of the case's plaintiff and defendant in versus format, separating the two parties by a ".v" for versus. Type a period after the defendant's name.
Type the section, clause or article number of the constitution on which the case can be found. Type the abbreviation for the case's jurisdiction after the section number. For example, type "G.A." if the case is taken from the Georgia Constitution -- type "U.S." for federal cases.
Type the case's page number after its jurisdiction. Finalize your citation by tagging the case's year to the end of it. Type the year in parenthesis. Save your document.