PCHELOV, E.V. Десять веков русской азбуки. Gosudarstvennaya Sluzhba, [S. l.], v. 6, n. 3, p. 138–150, 2004. Disponível em: https://gosudarstvennaya-sluzhba.owebs.ru/article/view/20368. Acesso em: 9 nov. 2026.