Columbia subject headings:
Poetry, Modern--20th century--History and criticism.
Poetry, Modern--21st century--History and criticism.
Harvard subject headings:
German poetry--20th century--History and criticism
German poetry--21st century--History and criticism.
Poetry, Modern--20th century--History and criticism
Poetry, Modern--21st century--History and criticism
Princeton subject headings:
Poetry--20th century--History and criticism.
Poetry--21st century--History and criticism.