Izvestiya of Saratov University.

Mathematics. Mechanics. Informatics

ISSN 1816-9791 (Print)

ISSN 2541-9005 (Online)

однородное дифференциальное выражение с постоянными коэффициентами

On 2-fold completeness of the eigenfunctions for the strongly irregular quadratic pencil of differential operators of second order

On Multiple Completeness of the Root Functions for a Class of the Pencils of Differential Operators