Martin Skjekkeland. "dialekter i Norge". Store norske leksikon. Retrieved February 1, 2017.
"dialekter i Setesdal - Store norske leksikon". Retrieved 4 January 2015. Authors state that the Setesdal dialect is "perhaps the most distinctive and most difficult to understand" among all Norwegian dialects.
vallemal.no
To hear them pronounced, go to "Talemålet i Valle og Hylestad". Retrieved 4 January 2015. The section Uttale av vokalane needs to be selected manually.