Columbia subject headings:
Spanish literature--19th century--History and criticism.
Spanish literature--20th century--History and criticism.
Unamuno, Miguel de, 1864-1936--Criticism and interpretation.
Harvard subject headings:
Spanish literature--19th century--History and criticism
Spanish literature--20th century
Spanish literature--20th century--History and criticism
Unamuno, Miguel de,--Criticism and interpretation.
Princeton subject headings:
Unamuno, Miguel de, 1864-1936--Philosophy.