KALCHUK, I. V.; KHARKEVYCH, Yu. I. Approximation of (ψ, β)-differentiable functions by Weierstrass integrals. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 59, n. 7, p. 953–978, 2007. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3359. Acesso em: 5 dec. 2025.