@article{1178241525,
author = {Butzer, P. L. and Nessel, R. J. and Trebels, W.},
title = {On summation processes of Fourier expansions in Banach spaces, I. Comparison theorems},
journal = {Tohoku Math. J. (2)},
volume = {24},
number = {4},
year = {1972},
pages = { 127-140},
language = {en},
url = {http://dml.mathdoc.fr/item/1178241525}
}
Butzer, P. L.; Nessel, R. J.; Trebels, W. On summation processes of Fourier expansions in Banach spaces, I. Comparison theorems. Tohoku Math. J. (2), Tome 24 (1972) no. 4, pp. 127-140. http://gdmltest.u-ga.fr/item/1178241525/