One case may have multiple citations as different publishers (especially West and Lexis) may have published it in different reporter series.
Skafte v. Rorex: 553P.2d830 (Colo. 1976)
Legislation can be cited with numbers describing different stages of its process--its bill number, its public law number once passed, its citation once published in book-form with other laws, or its codified citation.
Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism (USA PATRIOT ACT) Act of 2001
Bill: H.R. 3162, 107th Cong. (2001)
Public law number: Pub.L. No. 107-56
Statutes at Large: 115 Stat. 272
US Code: 18 USCA § 1 nt. (2008)
California Environmental Quality Act (CEQA)
CA Chapter:1970 Cal. Stat. 2780 CA Code:Cal. Pub. Res. §§21000-21177 (2008)