Galkina T.I. , Alekseev A.S. , Bonch-Osmolovski M.M. , Eisenmenger W.. , Koblinger O.. , Lassmann K.. Termalisation of Nonequilibrium Acoustic Phonon Spectrum in a-Si:H. Pr. FIAH , N222 , 01.1985 Galkina T.I. , Bonch-Osmolovski M.M. , Eisenmenger W.. , Koblinger O.. , Lassmann K.. , Blinov A.Y. Down-Conversion of High-Frequency Acoustic Phonons. Phys. status solidi B , Vol.144,N2 , с. C.K87-K91 , 01.1987