Columbia subject headings:
Harvard subject headings:
Architects--Germany
Architecture--Germany--History--20th century
Architekten Kollhoff und Timmermann.
Kollhoff, Hans--Catalogs.
Kollhoff, Hans--Criticism and interpretation.
Timmermann, Helga--Catalogs.
Timmermann, Helga--Criticism and interpretation.
Princeton subject headings:
Architecture--Germany--21st century.
Architecture--Germany--History--20th century.
Architekten Kollhoff und Timmermann.
Kollhoff, Hans.
Timmermann, Helga.