Columbia subject headings:
Harvard subject headings:
Birds in literature.
Civilization, Medieval, in literature.
Debate poetry, English (Middle)--History and criticism.
English literature--Middle English, 1100-1500--History and criticism
Nightingale--In literature.
Princeton subject headings:
Birds in literature.
English literature--Middle English, 1100-1500--History and criticism.
Nightingale in literature.