1. A. I. Stepanets, ?Classes of functions defined on the real axis and their approximations by entire functions. I,? Ukr. Mat. Zh.,42, No. 1, 102?112 (1990).
2. A. I. Stepanets, Classification and Approximation of Periodic Functions [in Russian], Naukova Dumka, Kiev (1987).
3. A. I. Stepanets, ?Rate of convergence of Fourier series in the spaces ???,? Preprint, No. 86.66, Akad. Nauk UkrSSR, Inst. Mat., Kiev (1986).
4. A. I. Stepanets, ?Classification of periodic functions and rate of convergence of their Fourier series,? Izv. Akad. Nauk SSSR, Ser. Mat.,50, No. 1, 101?136 (1986).
5. A. I. Stepanets, ?Approximation by Fourier operators of functions defined on the real axis,? Ukr. Mat. Zh.,40, No. 2, 198?209 (1988).