31: 12-15: Quattuor libri principiorum - Lull, Ramón, <beato, ca.1232-1315>. (OLS)http://semarc/name/1156; Sánchez Manzano, María Asuncíon. (OLS)http://semarc/name/42226 (Raimundi Lulli Opera latina, 2006)