@Book{BVMC:292597,
author = {Unamuno, Miguel de},
title = {Tarjeta de Unamuno a Rafael Altamira. Salamanca, 23 de febrero de 1896},
publisher = {Alicante : Biblioteca Virtual Miguel de Cervantes, 2012},
year = {2012},
url = {https://www.cervantesvirtual.com/nd/ark:/59851/bmcnk415}
}