PRATSIOVYTYI, M. V.; KLYMCHUK, S. O.; MAKARCHUK, O. P. Level sets of asymptotic mean of digits function for $4$-adic representation of real number. Methods of Functional Analysis and Topology, [S. l.], v. 22, n. 2, p. 184–196, 2016. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/635. Acesso em: 16 dec. 2025.