%0 Journal Article %A S. S. Grigoryan %T On the nature of ``super deep'' penetration of solid microparticles in hard materials %J Doklady Akademii Nauk %D 1987 %P 1319-1323 %V 292 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1987_292_6_a9/ %G ru %F DAN_1987_292_6_a9