M. M. Bilyi, I. S. Gorban, I. M. Dmitruk, I. M. Salivonov, and I. V. Ostrovskii, Acoustically stimulated phase transition and low temperature optical spectra in PbI₂ crystal, Low Temp. Phys. 24, (1998) [Fiz. Nizk. Temp. 24, 807-808, (1998)] DOI: https://doi.org/10.1063/1.593644.