Columbia subject headings:
Architecture, Modern--19th century.
Architecture, Modern--20th century.
Monuments.
Symbolism in architecture.
Harvard subject headings:
Architecture, Modern--19th century
Architecture, Modern--21st century
Monuments
Symbolism in architecture.
Princeton subject headings:
Architecture, Modern--19th century.
Architecture, Modern--20th century.
Monuments.
Symbolism in architecture.