History of Spain
In the Burgos prison, he made the acquaintance of many intellectuals and university professors. It was there that Francisco Jordá (later a professor of archaeology) convinced him to undertake university studies. Difficulties prevented him from doing so until 1948. Two books played a large role in motivating him: the "Manual de Gramática Española" ("Manual of Spanish Grammar") by Menéndez Pidal and Aguado Bleye's "History of Spain".