@article{GDZPPN002484307, title = {Quadratic Integrals of Linear Hamiltonian Systems.}, journal = {Monatshefte f\"ur Mathematik}, volume = {98}, year = {1984}, pages = {53-64}, zbl = {0541.34021}, url = {http://dml.mathdoc.fr/item/GDZPPN002484307} }
Kocak, Hüseyin. Quadratic Integrals of Linear Hamiltonian Systems.. Monatshefte für Mathematik, Tome 98 (1984) pp. 53-64. http://gdmltest.u-ga.fr/item/GDZPPN002484307/