TUIRÁN, Rodolfo et al. Learning gains in higher middle education. Papeles de Población, [S.l.], v. 25, n. 100, p. 87-119, oct. 2019. ISSN 2448-7147. Available at: <https://rppoblacion.uaemex.mx/article/view/12247>. Date accessed: 18 aug. 2026.