PHASE TRANSITIONS AND EXCITONSRaman and infrared studies of librational-translational modes in stress-aligned ferroelastic KCN D. Durand, L. C. Scavarda do Carmo and F. Luty J. Phys. Colloques, 41 C6 (1980) C6-437 DOI: 10.1051/jphyscol:19806112