@article{VMUMM_1986_4_a4,
     author = {Yu. S. Ilyashenko},
     title = {Separatrix lunes of analytic vector fields on the plane},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {25--31},
     year = {1986},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1986_4_a4/}
}