1. Neimark, A.V., Electrophysical properties of a percolation layer of finite thickness, Zh. Eksp. Teor. Fiz., 1990, vol. 98, no. 2, p. 611.
2. Clerc, J.P., Alexander, S., and Guyon, E., Conductivity of a mixture of conducting and insulating grains: Dimensionality effects, Phys. Rev. B, 1980, vol. 22, p. 2489.
3. Shi, Ch.-Y., Hu, Zh.-B., and Hao, Y.-M., Structural, magnetic and dielectric properties of La2 –
xCaxNiO4 + δ (x = 0, 0.1, 0.2, 0.3), J. Alloys Compd., 2011, vol. 509, p. 1333.
4. Kerimov, M.K., Kurbanov, M.A., Sultanakhmedova, I.S., Faradzhzade, I.A., et al., Varistor effect in polymer-semiconductor composites, Semiconductors, 2010, vol. 44, no. 6, p. 904.
5. Kurtukova, L.V., Changes in the properties of bentonite clays under the influence of various activators, Polzunovskii Vestn., 2013, no. 1, p. 287.