{{Cite book| edition = Coédition BRGM-Omniscience| last1 = Graviou| first1 = Pierrick| last2 = Jegouzo| first2 = Pierre| last3 = Plaine| first3 = Jean| last4 = Jonin| first4 = Max| title = Bretagne, Guide Géologique| date = 2014}}