00648naa#a2200181#i#450# EN\\bibl\2887 /en/manage/index 20250213231604.4 2308-8877 20140616b2014####ek#y0engy0150####ca RUS RU Spectrum of a non -self-adjoint differential operators with block-triangular matrix coefficients Journal article Voronezh FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov 2014 4 с. Journal article local Kholkin A. test.editorum.ru /en/manage/index