https://text-message.blogs.archives.gov/2022/08/25/an-indige... contains paperwork from a legal case from 1974. Given that a lot of this happened back then, I don't think you'll find any "recent reputable" sources, but are you willing to accept older material?

There's also https://repository.lsu.edu/cgi/viewcontent.cgi?article=2129&...