70 years of the Soviet revolution. Revista Universidad de Guayaquil, [S. l.], v. 70, n. 3, p. 91–94, 1987. DOI: 10.53591/rug.v70i3.724. Disponível em: https://revistas.ug.edu.ec/index.php/rug/article/view/896. Acesso em: 5 dec. 2025.