@article{SM_1997_188_6_a6,
     author = {V. V. Filippov},
     title = {Homology properties of the~sets of solutions to ordinary},
     journal = {Sbornik. Mathematics},
     pages = {933--953},
     publisher = {mathdoc},
     volume = {188},
     number = {6},
     year = {1997},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1997_188_6_a6/}
}