D. M. Freik, Mudriy S. І., T. A. Kriskov, Gorіchok І. V., Matkіvsky O. M., and T. O. Semko, “Synthesis and Properties of Highly Efficient Thermoelectric Materials Based on Lead Telluride with Antimony and Silver Impurity”, Phys. Chem. Sol. State, vol. 16, no. 1, pp. 49–54, Mar. 2015.