Secondary sources are very useful and important. They provide a wide variety of information on the subject matter in research. Sometimes, multiple secondary sources must be used in order to understand the complexity of the legal question present, and the different implications the topic has. Secondary sources are a starting point of research, they are not binding authority. 

Native American Law, especially in dealing with sacred and religious sites, touches upon a variety of different subjects: environmental law, water rights, mining and oil rights, property rights, and religious freedoms.

American Indian Law Review Link - "The American Indian Law Review is a specialized law review devoted exclusively to Indian law, and provides a forum for scholarly writing in the areas of the law that particularly affect American Indians." 

Tribal Law Journal - "The Tribal Law Journal contains the full text of documents that are dedicated to the discussion of internal indigenous laws and issues that are of importance to students, practitioners, and academics."

Native American Law Emerging Issues - Published irregularly by Matthew Bender & Company, Inc.