Martínez Soto, Ángel Pascual, Miguel Ángel Pérez de Perceval Verde, and Jorge Eduardo Martínez Pérez. 2018. “Wages and Work Organization in the Southeast Spanish Mining, 1850-1936”. Revista De Historia Industrial — Industrial History Review 26 (69):49-79. https://revistes.ub.edu/index.php/HistoriaIndustrial/article/view/21501.