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@article{MZM_1991_50_4_a2, author = {A. S. Belov}, title = {Partial sums of a trigonometric series with convex coefficients}, journal = {Matemati\v{c}eskie zametki}, pages = {21--27}, publisher = {mathdoc}, volume = {50}, number = {4}, year = {1991}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MZM_1991_50_4_a2/} }
A. S. Belov. Partial sums of a trigonometric series with convex coefficients. Matematičeskie zametki, Tome 50 (1991) no. 4, pp. 21-27. http://geodesic.mathdoc.fr/item/MZM_1991_50_4_a2/