@article{MZM_2021_109_4_a3,
     author = {V. V. Yevstafyeva},
     title = {Existence of~$T/k${-Periodic} {Solutions} of a {Nonlinear} {Nonautonomous} {System} {Whose} {Matrix} {Has} a {Multiple} {Eigenvalue}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {529--543},
     publisher = {mathdoc},
     volume = {109},
     number = {4},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2021_109_4_a3/}
}