@article{SM_1970_12_3_a1,
     author = {Yu. S. Kolesov},
     title = {Periodic solutions of relay systems with distributed parameters},
     journal = {Sbornik. Mathematics},
     pages = {343--367},
     publisher = {mathdoc},
     volume = {12},
     number = {3},
     year = {1970},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1970_12_3_a1/}
}