Parfilova Oksana Vladimirovna Russia Saratov State Academy of Law, Russia, 410056, Saratov, Vol'skaya st., 1 Oksana_Parfilova@mail.ru Author's articles 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 of the Pencils of Differential Operators with Constant Coefficients
