Columbia subject headings:
Life on other planets in literature.
Monsters in literature.
Science fiction--History and criticism.
Harvard subject headings:
Life on other planets in literature--Congresses.
Life on other planets in literature.
Monsters in literature
Monsters in literature--Congresses.
Science fiction--History and criticism
Science fiction--History and criticism--Congresses
Princeton subject headings:
Life on other planets in literature.
Monsters in literature.
Science fiction--History and criticism.