@article{Łenski:2009,
author
=
"W.Łenski",
title
=
"On the norm-strong approximation of 2\pi-periodic functions",
journal
=
"Demonstratio Mathematica",
volume
=
"Vol. 11",
number
=
"no 2",
pages
=
"285--299",
year
=
"1978",
}