High-temperature X-ray diffraction and thermal expansion of nanocrystalline and coarse-crystalline acanthite α-Ag2S and argentite β-Ag2S / S. I. Sadovnikov, A. I. Gusev, A. V. Chukin, A. A. Rempel // PCCP: Physical Chemistry Chemical Physics. - 2016. - Vol. 18, № 6. - P. 4617-4626.