no. 3
A strengthened form of a theorem of Fejér
Compositio Mathematica, Tome 21 (1969) no. 3, pp. 262-270. 
@article{CM_1969__21_3_262_0,
     author = {Siddiqi, Jamil A.},
     title = {A strengthened form of a theorem of {Fej\'er}},
     journal = {Compositio Mathematica},
     pages = {262--270},
     publisher = {Wolters-Noordhoff Publishing},
     volume = {21},
     number = {3},
     year = {1969},
     mrnumber = {256062},
     zbl = {0177.31802},
     language = {en},
     url = {http://www.numdam.org/item/CM_1969__21_3_262_0/}
}
TY  - JOUR
AU  - Siddiqi, Jamil A.
TI  - A strengthened form of a theorem of Fejér
JO  - Compositio Mathematica
PY  - 1969
SP  - 262
EP  - 270
VL  - 21
IS  - 3
PB  - Wolters-Noordhoff Publishing
UR  - http://www.numdam.org/item/CM_1969__21_3_262_0/
LA  - en
ID  - CM_1969__21_3_262_0
ER  - 
%0 Journal Article
%A Siddiqi, Jamil A.
%T A strengthened form of a theorem of Fejér
%J Compositio Mathematica
%D 1969
%P 262-270
%V 21
%N 3
%I Wolters-Noordhoff Publishing
%U http://www.numdam.org/item/CM_1969__21_3_262_0/
%G en
%F CM_1969__21_3_262_0
Siddiqi, Jamil A. A strengthened form of a theorem of Fejér. Compositio Mathematica, Tome 21 (1969) no. 3, pp. 262-270. http://www.numdam.org/item/CM_1969__21_3_262_0/

L. Fejér [1 ] Ûber die Bestimmung des Sprunges einer Funktionen aus ihrer Fourierreihe, J. Reine Angew. Math, 142 (1913), 165-168. | EuDML | JFM

J.A. Siddiqi [2] Coefficient properties of certain Fourier series, Math. Ann., 181 (1969), 242-254. | EuDML | MR | Zbl

N. Wiener [3] The quadratic variation of a function and its Fourier coefficients, J. Math. and Phys. 3 (1924), 72-94. | JFM

A. Zygmund [4] Trigonometric Series vol. 1, Cambridge, 1959. | Zbl