@article{10_1017_S0017089500004365,
     author = {Berkson, Earl and Porta, Horacio},
     title = {The group of isometries on {Hardy} spaces of the n-ball and the polydisc},
     journal = {Glasgow mathematical journal},
     pages = {199--204},
     year = {1980},
     volume = {21},
     number = {2},
     doi = {10.1017/S0017089500004365},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500004365/}
}