Yin, Qiyi, et al. “Crystal Structure and Properties of Na2O-Modified K0.47Na0.47Li0.06Nb0.96Sb0.04O3-SrTiO3 Piezoelectric Ceramics”. Asian Journal of Chemistry, vol. 25, no. 10, May 2013, pp. 5655-7, doi:10.14233/ajchem.2013.OH51.