Low energy phonon spectrum and its parameterization in pure KTaO3 below 80 KE. Farhi, A. K. Tagantsev, R. Currat, B. Hehlen, E. Courtens and L. A. BoatnerEur. Phys. J. B, 15 4 (2000) 615-623DOI: https://doi.org/10.1007/s100510051164