Primary source: "La Solidaridad" newspaper; Secondary source: "Marcelo H. del Pilar: His Religious Conversions" book.
A copy of the biweekly Spanish newspaper "La Solidaridad," a primary source from the Reform Movement in Spain, displayed alongside a secondary source, the book "Marcelo H. del Pilar: His Religious Conversions" by Fidel Villarreal, OP.