Figure 7. Temperature dependence of resistivity for PbTe_0.92S_0.08 crystals doped with different amounts of In (on the left) and Se (on the right). The concentration of indium (in at.%): 1, 0.15; 2, 0.31; 3, 0.49; 4, 0.71. The concentration of Se in the samples of Pb(Te_1-ySe_y)_0.92S_0.08 (in mol.%): 5, 21; 6, 27; 7, 34; 8, 40; 9, 46 /20/.