PETROVA, T. O. One counterexample for convex approximation of function with fractional derivatives, r>4. Bulletin of Taras Shevchenko National University of Kyiv. Physics and Mathematics, [S. l.], n. 3, p. 53–56, 2018. DOI: 10.17721/1812-5409.2018/3.7. Disponível em: https://bphm.knu.ua/bphm/article/view/146. Acesso em: 15 oct. 2026.