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@article{MAT_1961_5_2_a8, author = {C. L. Siegel}, title = {On the integrals of canonical systems}, journal = {Matematika}, pages = {103--118}, publisher = {mathdoc}, volume = {5}, number = {2}, year = {1961}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MAT_1961_5_2_a8/} }
C. L. Siegel. On the integrals of canonical systems. Matematika, Tome 5 (1961) no. 2, pp. 103-118. http://geodesic.mathdoc.fr/item/MAT_1961_5_2_a8/