@article{SM_2002_193_11_a5,
     author = {V. V. Filippov},
     title = {On the existence of periodic solutions of equations with strongly increasing principal part},
     journal = {Sbornik. Mathematics},
     pages = {1707--1729},
     year = {2002},
     volume = {193},
     number = {11},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2002_193_11_a5/}
}