Fig. 2. R(T) curves for Pb_1-xSn_xTe_0.75Se_0.25 samples. 1 - x=0.075, 2 - x=0.2, 3 - x=0.3, 4 - x=0.5, 5 - x=0.625, 6 - x=0.85. Curves 2,3,6 are shifted up by 30, 50, and 80 units, respectively, and curve 4 is shifted down by 30 units. Samples 1,2 are of n-type, 3-6 - of p-type. Arrows indicate the direction of temperature change during recording the curves.