Krishnan, A, D.J Keeble, Ramamoorthy Ramesh, W.L Warren, B.A Tuttle, R.L Pfeffer, B Nielsen, and K.G Lynn. "Vacancy related defects in thin film Pb(ZrTi)O3 materials." Materials Research Society Symposium - Proceedings. Vol. 361. Materials Research Society, Pittsburgh, PA, United States, 1995. 129–134.