@article{ZNSL_2009_373_a1,
     author = {A. D. Bruno and V. F. Edneral},
     title = {On integrability of a~planar system of {ODEs} near a~degenerate stationary point},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {34--47},
     publisher = {mathdoc},
     volume = {373},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2009_373_a1/}
}