Morozovska, A. N., C. M. Scherbakov, and M. D. Glinchuk. “Dependence of Soft Phonon Spectra on Flexoelectric Coupling in Ferroelectrics”. Ukrainian Journal of Physics 63, no. 2 (March 2, 2018): 168. Accessed November 30, 2021. https://ujp.bitp.kiev.ua/index.php/ujp/article/view/118.