@article{1102866952,
author = {Garnett, John B. and O'Farrell, Anthony G.},
title = {Sobolev approximation by a sum of subalgebras on the circle.},
journal = {Pacific J. Math.},
volume = {67},
number = {2},
year = {1976},
pages = { 55-63},
language = {en},
url = {http://dml.mathdoc.fr/item/1102866952}
}
Garnett, John B.; O'Farrell, Anthony G. Sobolev approximation by a sum of subalgebras on the circle.. Pacific J. Math., Tome 67 (1976) no. 2, pp. 55-63. http://gdmltest.u-ga.fr/item/1102866952/