1) E. Galan, “Proc. Int'l Clay Conf. 1985, Denver”, (L. G. Schultz, H. van Olphen and F. A. Mumpton, eds.), The Clay Minerals., Indiana (1987), p. 400.
2) J. L. Martin Vivaldi and R. H. S. Robertson, “Electron Optical Investigation of Clays”, (J. A. Gard, ed.), Mineral. Soc. London (1971), p.255.
3) T. E. Bates, “Selected Electron Micrographs of Clays”, Mineral Industries Experimental Station, State Univ. Pennsylvania (1985), p. 45.
4) B. F. Jones and E. Galan, “Hydrous Phyllosilicates, Reviews in Mineralogy, Vol.19”, (S. W. Bailey,ed.), Mineral. Soc. of America, Michigan (1988), Chap. 16.