SokolenkoI. V., and StepanetsO. I. 2004. “Approximation of the $\bar {\Psi}$ -Integrals of Functions Defined on the Real Axis by Fourier Operators”. Ukrains’kyi Matematychnyi Zhurnal 56 (7), 960–965. https://umj.imath.kiev.ua/index.php/umj/article/view/3812.