Estimation of Dirichlet kernel difference in the norm of L / *V. O. Tonkov.* // Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika. 2010. № 1. P. 12-18
[Moscow Univ. Math. Bulletin. Vol. 72, N 2, 2017. P. 10-15].

This work is related to the problem of estimation of the norm of
a trigonometrical polynomials through their coefficient in L.
It is proved that the norm of the difference of Dirichlet's kernels
in L has the precise order

*Key words*:
norm of a trigonometrical polynomial in L, asymptotic estimate.