@article{CTT100773086,
  author = {H. Okudera and Y. Sakai and K. Yamagata and H. Takeda},
  title = {Structure of russellite (Bi2WO6): origin of ferroelectricity and the effect of a stereoactive lone electron pair on the structure},
  journal = {Acta Cryst. B},
  year = 2018,
}

@article{CTT100761104,
  author = {H. Takeda and K. Yoshida and H. Okudera and K. Lebbou and T. Hoshina and T. Tsurumi},
  title = {Growth and characterization of strontium-substituted Ca2Al2SiO7 piezoelectric single crystals},
  journal = {J. Ceram. Soc. Jpn.},
  year = 2017,
}