Pueyo Sánchez, Javier. “When Was Cement Industry an Oligopoly? The Spanish Case, 1908-1992”. Revista de Historia Industrial — Industrial History Review, no. 9 (April 27, 2017): 83–115. Accessed May 1, 2024. https://revistes.ub.edu/index.php/HistoriaIndustrial/article/view/18350.