Ajiev, S. S. “Hölder Analysis and Geometry on Banach Spaces: Homogeneous Homeomorphisms and Commutative Group Structures, Approximation and Tzar’kov’s Phenomenon. Part I”. Eurasian Mathematical Journal, vol. 5, no. 1, Mar. 2014, pp. 7-60, https://emj.enu.kz/index.php/main/article/view/561.