A. B.  Gaikwad, Navale, S. C., and Ravi, V., ?TiO2 ceramic varistor modified with tantalum and barium?, Materials Science and Engineering B-Solid State Materials for Advanced Technology, vol. 123, no. 1, pp. 50-52, 2005.

S. C.  Navale, A. Murugan, V., and Ravi, V., ?Varistors based on Ta-doped TiO2?, Ceramics International, vol. 33, no. 2, pp. 301-303, 2007.