Pérez Castroviejo, Pedro M. “Purchasing Power and Living Quality of the Biscayan Workers, 1876-1936”. Revista de Historia Industrial — Industrial History Review 15, no. 30 (July 24, 2017): 103–142. Accessed March 9, 2025. https://revistes.ub.edu/index.php/HistoriaIndustrial/article/view/19621.