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@article{AA_1991_3_5_a10, author = {V. A. Yakubovich}, title = {Nonoscillation of linear periodic {Hamiltonian} equations and related problems}, journal = {Algebra i analiz}, pages = {229--253}, publisher = {mathdoc}, volume = {3}, number = {5}, year = {1991}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/AA_1991_3_5_a10/} }
V. A. Yakubovich. Nonoscillation of linear periodic Hamiltonian equations and related problems. Algebra i analiz, Tome 3 (1991) no. 5, pp. 229-253. http://geodesic.mathdoc.fr/item/AA_1991_3_5_a10/