1. Léon Fleuriot,Grand Atlas de la France(Paris: Ed. S´lection de Reader's Digest, 1969), pp. 96–99 (on local languages in France).
2. See Ferdinand Brunot,Histoire de la langue française(Paris: Armand Colin, 1967), t. ix, 1, pp. 536–540.
3. Joseph Loth,Vocabulaire vieux-breton(Paris: Vieweg, 1883).
4. Joseph Loth,Chrestomathie bretonne(Paris: Bouillon, 1890).