PIERCE, Harmon R.; RICE, Leon E. A Survey of Changes in Achievement Levels of Ninth-Grade Pupils in Washington County White Schools, 1948 to 1958. Florida Journal of Educational Research, [S. l.], v. 2, n. 1, p. 47–52, 1960. Disponível em: https://journals.flvc.org/fjer/article/view/134070. Acesso em: 13 jan. 2025.