@article{guerra_eiras_2004,  title={High frequency dielectric relaxation in lanthanum modified PbTiO3 ferroelectric ceramics},  volume={7},  ISSN={1516-1439},  url={https://doi.org/10.1590/S1516-14392004000200017},  DOI={10.1590/S1516-14392004000200017},  number={2},  journal={Materials Research},  publisher={ABM, ABC, ABPol},  author={Guerra, José de los Santos and Eiras, José Antonio},  year={2004},  month={Apr},  pages={325–328} }