Tarasenko-Zelenaya , L. I., A. N. Zavarin, and S. L. Radvansky. 1988. “High-Frequency Kernel in the Algorithm of Function Restoration from the Projections for Diverging Beams”. Ukrains’kyi Matematychnyi Zhurnal 40 (2): 253-56. https://umj.imath.kiev.ua/index.php/umj/article/view/9128.