Columbia subject headings:
Heaney, Seamus, 1939-2013--Criticism and interpretation.
Harvard subject headings:
English language--20th century--Style
English language--Style
English poetry--Irish influences.
Heaney, Seamus, 1939-2013--Knowledge--Language and languages.
Northern Ireland--In literature.
Poetics
Poetics--History--20th century
Princeton subject headings:
Heaney, Seamus, 1939-2013--Criticism and interpretation.