Columbia subject headings:
Harvard subject headings:
Architectural drawing--20th century--Spain--Madrid.
Architectural drawing--Spain--Madrid--20th century--Catalogs.
Madrid (Spain)--Buildings, structures, etc.
Madrid (Spain)--Buildings, structures, etc.--Catalogs.
Palacio Real (Madrid, Spain)--Catalogs.
Palacio de Oriente (Spain)
Princeton subject headings:
Madrid (Spain)--Buildings, structures, etc.
Palacio Real (Madrid, Spain)