%0 Journal Article %A A. S. Kagan %A V. I. Fadeeva %A L. A. Panchenko %A A. P. Unikel %T Twin imperfections of packing in complex hexagonal crystals %J Doklady Akademii Nauk %D 1980 %P 357-359 %V 254 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1980_254_2_a22/ %G ru %F DAN_1980_254_2_a22