I. A. Pasynkova, “Letter to the editors ("The existence of families of periodic solutions of a system of <nobr>$n$</nobr> second order differential equations in the resonance case", Differencial'nye Uravnenija <b>5</b> (1969), 1984–1989)”, Differ. Uravn., 1973, Volume 9, Number 1,Page 192

Letters to the Editor

Letter to the editors ("The existence of families of periodic solutions of a system of $n$ second order differential equations in the resonance case", Differencial'nye Uravnenija 5 (1969), 1984–1989)

I. A. Pasynkova