@article{VMUMM_2011_6_a4,
     author = {I. N. Sergeev},
     title = {Oscillation and wandering of solutions to a second order differential equation},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {21--26},
     publisher = {mathdoc},
     number = {6},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2011_6_a4/}
}