Figure 8. Dependence of T
c
upon the concentration N
i
of different impurities for PbTe
0.92
S
0.08
. 1, Cd; 2, Ga; 3, In; 4, Tl; 5, Sb; 6, Bi; 7, Mn /20/. Dashed line corresponds to the isoelectronic impurity Se.