Columbia subject headings:
Architecture, Modern--21st century.
Architecture--Germany--Hamburg--History--21st century.
Sustainable architecture--Case studies--Exhibitions.
Harvard subject headings:
Architecture, Modern--21st century
Architecture--Germany--Hamburg--21st century.
Sustainable architecture--Case studies--Exhibitions.
Princeton subject headings:
Architecture, Modern--21st century--Exhibitions.
Case studies.
Sustainable architecture--Case studies--Exhibitions.