Columbia subject headings:
Besteiro, Julián, 1870-1940--Correspondence.
Political prisoners--Spain--Correspondence.
Socialism--Spain.
Harvard subject headings:
Besteiro, Julián, 1870-1940--Correspondence.
Political prisoners--Spain--Correspondence.
Socialism--Spain
Princeton subject headings:
Besteiro, Julián, 1870-1940--Correspondence.
Political prisoners--Spain--Correspondence.
Socialism--Spain.