“Structural and Piezoelectric Properties of Rare Earth-Doped PT Ceramics” E. Dimitriu, I. Boerasu, M. Pereira, M.J.M. Gomes, C.Tanasoiu “10th International Meeting on Ferroelectricity-IMF10”, 3-7 de Setembro de 2001, Madrid, Espanha. http://www.imf10.etsit.upm.es/