@article{MZM_2011_89_4_a7,
     author = {D. V. Poplavsky},
     title = {Completeness {Theorem} for {Singular} {Differential} {Pencils}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {558--576},
     publisher = {mathdoc},
     volume = {89},
     number = {4},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2011_89_4_a7/}
}