S.F.S. Design keystone-shaped concrete block. Materiales de Construcción, [S. l.], v. 6, n. 071, p. 38–38, 1956. DOI: 10.3989/mc.1956.v06.i071.2397. Disponível em: https://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/2397. Acesso em: 3 may. 2024.