Columbia subject headings:
Harvard subject headings:
Airport buildings--Germany--Halle.
Architects--Switzerland.
Architecture, Modern--20th century--Designs and plans
Architecture, Modern--20th century--Switzerland--Designs and plans.
Wittwer, Hans, 1894-1952.
Princeton subject headings:
Architecture, Modern--20th century--Catalogs.
Catalogs.
Wittwer, Hans, 1894-1952--Catalogs.