00605naa#a2200169#i#450# EN\\bibl\3133 20250414031817.1 2308-8877 20140617b2014####ek#y0engy0150####ca RUS RU On multiple completeness of the root functions Of the sameclass of pencils of differential operators Journal article Voronezh FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov 2014 3 с. Journal article local Rykhlov V. anni.editorum.ru