@Book{BVMC:773326, author = {Alfonso XII, Rey de España}, title = {Carta del príncipe Alfonso a su madre Isabel, Viena, 27 abril 1874}, publisher = {Alicante : Biblioteca Virtual Miguel de Cervantes, 2017}, year = {2017}, url = {https://www.cervantesvirtual.com/nd/ark:/59851/bmc379b8} }