SvistunO. P. (1994) “On the existence of piecewise-continuous separatrix curves for a certain class of pulse systems”, Ukrains’kyi Matematychnyi Zhurnal, 46(5), pp. 580–585. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5720 (Accessed: 24November2024).