BaranovichA. M. and DaletskiiY. L. (1996) “Some geometric-differential models in the class of formal operator power series”, Ukrains’kyi Matematychnyi Zhurnal, 48(6), pp. 739-746. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5274 (Accessed: 6October2024).