The following resources can assist you with citing foreign and international legal materials.
The Bluebook by
A Uniform System of Citation: The Bluebook is the definitive style guide for legal citation in the United States. For generations, law students, lawyers, scholars, judges, and other legal professionals have relied on The Bluebook's uniform system of citation in their writing. In a diverse and rapidly changing legal profession, The Bluebook continues to provide a systematic method by which members of the profession communicate important information to one another about the sources and legal authorities upon which they rely in their work.
Guide to Foreign and International Legal Citations by 
International Citator and Research Guide: The Greenbook by
"The ICRG set, conveniently organized into global regions, is a source of foundational and comprehensive citation standards for scholars working with all types of international and foreign materials. It presents each citation standard in the context of that country or organization’s history and legal institutions. . . . It can be used as a companion to The Bluebook, whose coverage of international sources is limited." - Publisher