Fizika Tverdogo Tela, 1991 Volume 33, Issue 7,Pages 1952–1956(Mi ftt6934)
Electroacoustic effect in $\{\mathrm{N}(\mathrm{CH}_{3})_{4}\}_{2}\mathrm{ZnCl}_{4}$ and $\{\mathrm{N}(\mathrm{CH}_{3})_{4}\}_{2}\mathrm{CoCl}_{4}$ crystals near the incommensurate-to-polar phase transition