Columbia subject headings:
Lucha de clases (Bilbao, Spain)
Socialism--Spain--History--19th century.
Unamuno, Miguel de, 1864-1936--Criticism and interpretation.
Unamuno, Miguel de, 1864-1936--Political and social views.
Harvard subject headings:
Lucha de clases (Bilbao, Spain)
Socialism--Spain--History--19th century.
Socialism.
Unamuno, Miguel de, 1864-1936--Criticism and interpretation.
Unamuno, Miguel de, 1864-1936--Political and social views.
Princeton subject headings:
Lucha de clases (Bilbao, Spain)
Socialism.
Unamuno, Miguel de, 1864-1936--Political and social views.