@article{ELA_2004__11__a6,
     author = {Mehl, Christian and Ran, Andr\'e C.M. and Rodman, Leiba},
     title = {Hyponormal matrices and semidefinite invariant subspaces in indefinite inner products},
     journal = {The electronic journal of linear algebra},
     pages = {192--204},
     publisher = {mathdoc},
     volume = {11},
     year = {2004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ELA_2004__11__a6/}
}