@article{ELA_2008__17__a27,
     author = {Mehrmann, Volker and Xu, Hongguo},
     title = {Perturbation of purely imaginary eigenvalues of {Hamiltonian} matrices under structured perturbations},
     journal = {The electronic journal of linear algebra},
     pages = {234--257},
     publisher = {mathdoc},
     volume = {17},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ELA_2008__17__a27/}
}