Fizika Tverdogo Tela, 1992 Volume 34, Issue 5,Pages 1491–1495(Mi ftt7497)
New arguments for the off-center position of tin atoms in $\mathrm{Pb}_{1-x}\mathrm{Sn}_{x}\mathrm{Te}_{1-y}\mathrm{Se}_{y}$ and $\mathrm{Pb}_{1-x}\mathrm{Sn}_{x}\mathrm{Te}_{1-y}\mathrm{S}_{y}$