Georgii G. Magaril-Il yaev, Konstantin Yu. Osipenko, Vladimir M. Tikhomirov. On Exact Values of n-Widths in a Hilbert Space. Journal of Approximation Theory, 108(1):97-117, 2001. [doi]
@article{Magaril-IlyaevOT01,
title = {On Exact Values of n-Widths in a Hilbert Space},
author = {Georgii G. Magaril-Il yaev and Konstantin Yu. Osipenko and Vladimir M. Tikhomirov},
year = {2001},
doi = {10.1006/jath.2000.3497},
url = {http://dx.doi.org/10.1006/jath.2000.3497},
researchr = {https://researchr.org/publication/Magaril-IlyaevOT01},
cites = {0},
citedby = {0},
journal = {Journal of Approximation Theory},
volume = {108},
number = {1},
pages = {97-117},
}