Fizika Tverdogo Tela, 1985 Volume 27, Issue 3,Pages 858–864(Mi ftt1849)
Concentration dependence of temperature and phase transition character in $(\mathrm{Pb}_{y}\mathrm{Sn}_{1-y})_{2}\mathrm{P}_{2}\mathrm{S}_{6}$ and $(\mathrm{Pb}_{y}\mathrm{Sn}_{1-y})_{2}\mathrm{P}_{2}\mathrm{Se}_{6}$