@article{DE_2004_40_4_a3,
     author = {G. Marino and R. Toscano},
     title = {Periodic {Solutions} of a {Class} of {Nonlinear} {Systems} of {Ordinary} {Differential} {Equations}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {465--476},
     publisher = {mathdoc},
     volume = {40},
     number = {4},
     year = {2004},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2004_40_4_a3/}
}