SerdyukA. S., StepanetsO. I. and ShydlichA. L. (2007) “On some new criteria for infinite differentiability of periodic functions”, Ukrains’kyi Matematychnyi Zhurnal, 59(10), pp. 1399–1409. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/3398 (Accessed: 22November2024).