Columbia subject headings:
Belief and doubt in literature.
Leopardi, Giacomo, 1798-1837--Criticism and interpretation.
Leopardi, Giacomo, 1798-1837--Philosophy.
Harvard subject headings:
Doubt in literature.
Leopardi, Giacomo, 1798-1837--Criticism and interpretation.
Leopardi, Giacomo, 1798-1837--Philosophy.
Princeton subject headings:
Leopardi, Giacomo, 1798-1837--Philosophy.