Columbia subject headings:
Architecture--Belgium--History--20th century.
Kroll, Lucien--Themes, motives.
Harvard subject headings:
Architects--Belgium.
Architecture, Modern--20th century--Belgium.
Kroll, Lucien--Themes, motives.
Princeton subject headings:
Architecture, Modern--20th century--Belgium.
Kroll, Lucien--Themes, motives.