@article{ARM_1989__25_4_a4,
     author = {Do\v{s}l\'a, Zuzana},
     title = {Singular quadratic functionals and transformation of linear {Hamiltonian} systems},
     journal = {Archivum mathematicum},
     pages = {223--234},
     publisher = {mathdoc},
     volume = {25},
     number = {4},
     year = {1989},
     mrnumber = {1188066},
     zbl = {0825.34020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1989__25_4_a4/}
}