History teaching in the soviet school of the 1920s - 1930s: (for example, schools in the city of kazan). Revista San Gregorio, [S. l.], v. 5, n. 20, p. 72–79, 2017. Disponível em: https://revista.sangregorio.edu.ec/index.php/REVISTASANGREGORIO/article/view/517. Acesso em: 28 dec. 2025.