S. Pattanayak, N. Panda, R. N. P. Choudhary, and A. Kumar, “Effect of Multiple Substitutions (Pb, Ti, Zr) on Structural, Permittivity and Electrical Properties of BiFeO3 Ceramics”, JAP, vol. 13, no. 4, pp. 4810–4820, Apr. 2017.