STUPKA, A. A. Long-Wave Optical Vibrations in Diatomic Ionic Crystals. Ukrainian Journal of Physics, [S. l.], v. 60, n. 6, p. 528, 2019. DOI: 10.15407/ujpe60.06.0528. Disponível em: https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2019223. Acesso em: 7 feb. 2023.