Columbia subject headings:
Harvard subject headings:
Authors, Spanish--20th century--Correspondence
Unamuno, Miguel de, 1864-1936--Friends and associates--Correspondence.
Unamuno, Miguel de, 1864-1936. Correspondence.
Princeton subject headings:
Authors, Spanish--20th century--Correspondence.
Unamuno, Miguel de, 1864-1936--Correspondence.
Unamuno, Miguel de, 1864-1936--Friends and associates--Correspondence.