Брисіна, І. В., and В. О. Макарічев. 2016. “Approximation Properties of Generalized Fup-Functions”. Visnyk of V. N. Karazin Kharkiv National University. Ser. Mathematics, Applied Mathematics and Mechanics 84 (December), 61-92. https://doi.org/10.26565/2221-5646-2016-84-06.