%0 Journal Article %A B. I. Birger %T Complex viscosity and Boussinesq approximation in the analysis of Earth upper mantle convective instability %J Doklady Akademii Nauk %D 1977 %P 794-797 %V 235 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1977_235_4_a17/ %G ru %F DAN_1977_235_4_a17