R. I. Eglitis, E. A. Kotomin, A. I. Popov, S. P. Kruchinin, and Ran Jia, Comparative ab initio calculations of SrTiO₃, BaTiO₃, PbTiO₃, and SrZrO₃ (001) and (111) surfaces as well as oxygen vacancies , Low Temp. Phys. 48, (2021) [Fiz. Nyzk. Temp. 48, 87-96, (2021)] DOI: https://doi.org/10.1063/10.0008968.