On Line Catalogue of Spanish Soccer cards 1905-2019
 

You can access totally free the online site fot the "Catálogo de cromos de fútbol en España 1905-2019". The address is: http://cromosdefutbol.net

More than 1700 collections referenced and a lot of info, descriptions, images, checklists.
Authors: Joseba Moro and Francisco García Cubero

Enjoy!!!