(1)
Vakarchuk, S. .; Vakarchuk, M. Approximation in the Mean of the Classes of Functions in the Space $L_2[(0,1);X]$ by the Fourier–Bessel Sums and Estimates of the Values of Their $n$-Widths. Ukr. Mat. Zhurn. 2024, 76 (2), 198-223. https://doi.org/10.3842/umzh.v76i2.7763.