Columbia subject headings:
Balloons in literature.
European literature--19th century--History and criticism.
Literature and society.
Movement in literature.
Quietude in literature.
Harvard subject headings:
Balloons in literature.
European literature--19th century--History and criticism.
Literature and society.
Movement in literature.
Quietude in literature.
Princeton subject headings:
Knowledge, Sociology.
Literature and society.
Literature, Modern--19th century--History and criticism.
Symbolism in literature.