@article{10_1017_S0017089500003438,
     author = {Kyle, J.},
     title = {Ranges of {Lyapunov} transformations for {Hilbert} space},
     journal = {Glasgow mathematical journal},
     pages = {99--101},
     year = {1978},
     volume = {19},
     number = {1},
     doi = {10.1017/S0017089500003438},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003438/}
}