Lower bound for the best approximations of periodic summable functions of two variables and their conjugates in terms of Fourier coefficients von Kononovych, T. O., Кононович, Т. О.

Volltext

Estimate for the Best Approximation of Summable Functions of Two Variables in Terms of Fourier Coefficients von Kononovych, T. O., Кононович, Т. О.

Volltext

Estimate for the Best Approximation of Summable Functions of Several Variables with a Certain Symmetry of Fourier Coefficients von Kononovych, T. O., Кононович, Т. О.

Volltext