CALVO CALVO, Ángel. The telephone in Spain: regulation without an independent regulator, 1882-1975. Revista de Historia Industrial — Industrial History Review, [S. l.], v. 25, n. 61, p. 141–182, 2018. DOI: 10.1344/rhi.v25i61.21334. Disponível em: https://revistes.ub.edu/index.php/HistoriaIndustrial/article/view/21334. Acesso em: 26 jul. 2024.