Petryk I, Lutsiuk Y, Kramar V. Frequency spectrum and group velocities of acoustic phonons in PbI2 nanofilms. Phys.Chem.Sol.State [Internet]. 2022 Aug. 24 [cited 2024 Oct. 16];23(3):478-83. Available from: https://ktipe.pnu.edu.ua/index.php/pcss/article/view/5733