Heiber, J., Clemens, F., Helbig, U., de Meuron, A., Soltmann, C., Graule, T., & Hülsenberg, D. (2007). Properties of Pb(Zr, Ti)O3 fibres with a radial gradient structure. Acta Materialia, 55(19), 6499-6506. https://doi.org/10.1016/j.actamat.2007.08.004