@article{MOMA_1984__98_178190,
     author = {H\"useyin Kocak},
     title = {Quadratic {Integrals} of {Linear} {Hamiltonian} {Systems.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {53--64},
     publisher = {mathdoc},
     volume = {98},
     year = {1984},
     zbl = {0541.34021},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1984__98_178190/}
}