%0 Journal Article %A M. P. Volarovich %A A. I. Levykin %A N. E. Galdin %T Speeds of longitudinal waves in rock samples at pressures of up to 20 000 kg/cm$^2$ %J Doklady Akademii Nauk %D 1964 %P 1349-1351 %V 157 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1964_157_6_a20/ %G ru %F DAN_1964_157_6_a20