@Book{BVMC:783071, author = {Unamuno, Miguel de}, title = {Sobre la tumba de Costa. A la más clara memoria de un espíritu sincero}, publisher = {Alicante : Biblioteca Virtual Miguel de Cervantes, 2017}, year = {2017}, url = {https://www.cervantesvirtual.com/nd/ark:/59851/bmc321z5} }