Čermáková Zdeňka, Bezdička Petr, Němec I., Hradilová J., Šrein V., Blažek Jan, Hradil David :  Naturally irradiated fluorite as a historic violet pigment: Raman spectroscopic and X-ray diffraction study , Journal of Raman Spectroscopy vol.46, 2 (2015), p. 236-243 [2015] DOI: 10.1002/jrs.4627