Calligaro, T., et al. "Dating Study of Two Rock Crystal Carvings by Surface Microtopography and by Ion Beam Analyses of Hydrogen." Applied physics. A, Materials Science & Processing 94/4 (2009): 871-878.

Calligaro, T., et al. "Dating Study of Two Rock Crystal Carvings by Surface Microtopography and by Ion Beam Analyses of Hydrogen." Applied physics. A, Materials Science & Processing 94/4 (2009): 871-878.