Vakarchuk, S. B., Вакарчук, С. Б., & Вакарчук, С. Б. (2002). On the Best Polynomial Approximations of $2π$-Periodic Functions and Exact Values of $n$-Widths of Functional Classes in the Space $L_2$. Institute of Mathematics, NAS of Ukraine.
Chicago Style (17th ed.) CitationVakarchuk, S. B., С. Б Вакарчук, and С. Б Вакарчук. On the Best Polynomial Approximations of $2π$-Periodic Functions and Exact Values of $n$-Widths of Functional Classes in the Space $L_2$. Institute of Mathematics, NAS of Ukraine, 2002.
MLA (8th ed.) CitationVakarchuk, S. B., et al. On the Best Polynomial Approximations of $2π$-Periodic Functions and Exact Values of $n$-Widths of Functional Classes in the Space $L_2$. Institute of Mathematics, NAS of Ukraine, 2002.
Warning: These citations may not always be 100% accurate.