Salas Suárez, Y., O. . Calzadilla González, and D. C. . Peña Infante. “The Training of the University Student for the Treatment of the Contents of the Multigrade School”. Didáctica Y Educación ISSN 2224-2643, vol. 14, no. 4, Oct. 2023, pp. 231-50, https://revistas.ult.edu.cu/index.php/didascalia/article/view/1809.