Columbia subject headings:
Architecture, Modern--21st century.
Skyscrapers--Designs and plans.
Tall buildings--Competitions.
Visionary architecture.
Harvard subject headings:
Architecture, Modern--21st century
Skyscrapers--Designs and plans.
Tall buildings--Competitions.
Visionary architecture.
Princeton subject headings:
Architecture, Modern--21st century.
Skyscrapers--Designs and plans.
Tall buildings--Competitions.
Visionary architecture.