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On stability of solutions to quasilinear periodic systems of differential equations. Demidenko, G.V.; Matveeva, I.I. — 2004 Sibirskij Matematicheskij Zhurnal
Stability of solutions to delay differential equations with periodic coefficients of linear terms. Demidenko, G.V.; Matveeva, I.I. — 2007 Sibirskij Matematicheskij Zhurnal