@article{ISU_2009_9_2_a8,
     author = {O. V. Shigaeva},
     title = {Multiple non-completeness for the system of eigenfunctionsof a~class of the pencils of ordinary differential operators},
     journal = {Izvestiya of Saratov University. Mathematics. Mechanics. Informatics},
     pages = {50--59},
     publisher = {mathdoc},
     volume = {9},
     number = {2},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ISU_2009_9_2_a8/}
}