1. W.D. Kingery, H.K. Bowen, D.R. Uhlmann, Introduction to Ceramics, Second Edition, Wiley, 1960, 1976, 143–162, 188–197.
2. Barium titanate as a barrier layer semiconductor;Heywang;Solid State Electron,1961
3. Resistivity anomaly in doped barium titanate;Heywang;J. Am. Ceram. Soc.,1964
4. Some aspects of semiconducting barium titanate;Jonker;Solid State Electron,1964
5. Defect chemistry and Electrical conductivity of doped barium titanate ceramics, part I, electrical conductivity at high temperatures of donor-doped barium titanate ceramics;Daniels;Philips Res. Rep.,1976