Nomirovs'kii, D.A. (2004) “On Homeomorphisms Realized by Certain Partial Differential Operators”, Ukrains’kyi Matematychnyi Zhurnal, 56(12), pp. 1707–1716. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/3878 (Accessed: 5 December 2025).