This is at least true for the Norwegians. Bygdebok and the Sami Don't expect to find any information about the Sami in a bygdebok written by a Norwegian before 1980 or even later than that. And if you find some Sami history there it will in most cases be inaccurate and given far less attention than it deserves. This reflects attitudes with roots back in times when the Sami culture was looked upon as inferior compared with Norwegian culture. Sami genealogy information appears in more or less the same sources as the majority people do, at least in Norway and Sweden.
Every dialect group seems to have a genealogy project going on.
He tells about his experience with Sami genealogy research. Years ago many genealogists stopped the research on an ancestry line when a Sami appeared there.