Example of a federal statute:
If possible, you should cite to the current official code or the supplement. Otherwise, cite a current unofficial code or its supplements. If these are unavailable, instead cite to (in order of decreasing preference) the official session laws, privately published session laws (like United States Code Congressional and Administrative News), a commercial electronic database (Westlaw, Lexis, etc.), a looseleaf service, an internet source, or even a newspaper if necessary.
A new edition of the official United States Code is only published every six years, with a cumulative supplement published annually. Thus, federal statutes that are enacted after the most recent edition or supplement to the U.S.C. should be cited using an unofficial code, such as West's U.S.C.A., until the statue appears in the U.S.C. Keep in mind that citations to most state codes must still cite to the most recent officially published code, specified by year.
You should give the statute's name and original section number only if it is commonly cited that way, or if it would aid the identification of the statue. If you are citing to a statute that is no longer in force, you should cite to the current code if the statute still appears in it. If it does not, cite to the last edition of the code in which it appeared.
Example of single section of the U.S. Code: 17 U.S.C. § 106.
Example of a state statute: Tex. Water Code Ann. § 5.013 (West 2008).
Bluebook Rule (21st): 12
If possible, statutory citations should always be to the current, official code for that jurisdiction. If a current official code does not exist (as is the case for many states), or if the statute is not yet published in an official codification, a citation to a current, unofficial code is preferred.
Unofficial, commercial publications are often published much more frequently and quickly than official publications. Because of this, citations for relatively recent statutes will typically be to an unofficial code.
At the Federal level, the official code publication is the United States Code (U.S.C.). There are also two unofficial codes, the United States Code Annotated (U.S.C.A) and the Untied States Code Service (U.S.C.S.).
Table T1 will indicate if a state has an official code or if there are multiple unofficial codes and will indicate the preferred citation order, if any.
Bluebook Rule (21st): 12.3.1(a)
In general, a statute's name should only be included in a citation if the statute is commonly cited by name.
Do not include an initial "The" as part of the statute name.
It is permissible to use either an official or popular name. It is also permissible to use both, placing the popular name in parenthesis.
Example: Digital Millennium Copyright Act (DMCA) § 103, 17 U.S.C. § 1201 (2006).
Bluebook Rule (21st): 12.3.1
The U.S. Code, and many state codes, are arranged by numeric titles.
You can read more about "Federal Statutes" here
To cite to a section of the U.S. Code:
Statutes dealing with copyright are codified in Title 17 of the U.S. Code. The Fair Use standards can be found at section 107. To cite this section of the code:
17 U.S.C. § 107 (Year) - Official U.S. Code
17 U.S.C.A. § 107 (Year) - Unofficial United States Code Annotated
17 U.S.C.S. § 107 (Year) - Unofficial United States Code Service
Bluebook Rule (21st): 12.3.2 & 12.5
Properly citing the year of a code section was historically the most complex aspect of a Bluebook statute citation. The traditional rule strictly required citation to a print version of the code, and the year used in the citation was based upon the publication schedule of the code volume rather than anything related to the section cited itself. The 21st edition essentially abandoned this requirement for federal statutes. Rule 12.3.2 now specifies that citations to a federal code, whether official or unofficial, do not require a date. However, the 21st edition retained rule 12.5, which generally requires that currency information be provided for citations to codes in digital databases, as discussed below.
Digital rule
The Bluebook holds that if you cite a code in an electronic database, you should note the database and its currency in a parenthetical.
Example: Cal. Civ. Code 1620 (West, Westlaw through 2012 portion of 2011-2012 Reg. Sess.).
However, when states only publish their statutes online, the online source can be cited directly.