Legal citation is the style of crediting and referencing other documents or sources of authority in legal writing.
In addition to the basic rules of footnoting and quotation that closely follows regular citation rules, there are several broad classes of law citation:

Case citation
Legislative citation
Treaty citation
Government document citation
Law periodical citation Citation by country
Each country usually has at least one de facto citation standard that has been adopted by most of the country's institutions.

Australian legal citation usually follows the Australian Guide to Legal Citation (commonly known as AGLC)
Canadian legal citation usually follows the Canadian Guide to Uniform Legal Citation (commonly called the McGill Guide)
U.S. legal citation follows either the Bluebook standard or the competing ALWD Citation Manual
Dutch legal citation follows the Leidraad voor juridische auteurs [1] (commonly known as Leidraad)
Citation of United Kingdom legislation is covered in Statutory Instrument Practice