For a comprehensive introduction to American Indian law see Angelique Townsend Eaglewoman and Stacy L. Leeds, Mastering American Indian Law and Federal Indian Law by Matthew L.M. Fletcher.
Three Supreme Court cases, known as the Marshall Trilogy, form the basis of Federal American Indian law:
In addition, each tribe also has a body of primary law, consisting of tribal court decisions, statutes and regulations, administrative agency materials, and tribal customs. See the Tribal Law tab for information on accessing these materials.