@article{10_1017_S0017089500000161,
     author = {Putnam, R.},
     title = {Hilbert transforms and unitary equivalence},
     journal = {Glasgow mathematical journal},
     pages = {113--117},
     year = {1967},
     volume = {8},
     number = {2},
     doi = {10.1017/S0017089500000161},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500000161/}
}