1. Anagnostopoulos T, Calamiotou M, Sideris C (1973) Magnetic behaviour of some biotite samples from Thrace, NE Greece. Clays Clay Miner 21:459?464
2. Annersten H (1974) Mössbauer studies of natural biotites. Am Mineral 59:143?151
3. Bailey SW (1980) Structures of layer silicates. In: Brindley GW, Brown G (eds) Crystal structures of clay minerals and their X-ray identification. London, Mineralogical Society, pp 1?124
4. Ballet O, Coey JMD, Massenet O (1979) Electric field gradient at Fe2+ sites is trioctahedral layer silicates. J Phys. (Paris) Colloq 40:C2 283?285
5. Beausoleil N, Lavallée P, Yelon A, Ballet O, Coey JMD (1982) Magnetic properties of biotite micas. J Appl Phys (in press)