Gramatica Moderna de La Lengua Japonesa

The upload to archive.org was basically botched up, so no ebook link is available to borrow directly from here. Until that is sorted out, a digitalized PDF copy is available at this Internet Archive address:
https://archive.org/details/GramaticaModernaDeLaLenguaJaponesa

As good as it is old, this edition can still be found easily for its original price, $30 give or take, in sites like todocoleccion.net or iberlibro.com, rather than a grand as I see occasionally in an Amazon ad here (!)