%0 Journal Article %A A. S. Vaidzelevich %T On spectra of upper Sergeev frequencies of linear differential equations %J Journal of the Belarusian State University. Mathematics and Informatics %D 2019 %P 28-32 %V 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/BGUMI_2019_1_a3/ %G ru %F BGUMI_2019_1_a3