Columbia subject headings:
Madrid (Spain)--Buildings, structures, etc.
Palaces--Spain--Madrid--History.
Palacio Real (Madrid, Spain)
Harvard subject headings:
Madrid (Spain)--Buildings, structures, etc.
Palaces--Spain--Madrid--History.
Palacio Real (Madrid, Spain)
Princeton subject headings:
Madrid (Spain)--Buildings, structures, etc.
Palaces--Spain--Madrid--History.
Palacio Real (Madrid, Spain)