MaksimenkoS. I. (2010) “Period functions for $\mathcal{C}^0$- and $\mathcal{C}^1$-flows”, Ukrains’kyi Matematychnyi Zhurnal, 62(7), pp. 954–967. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/2928 (Accessed: 23November2024).