Columbia subject headings:
City planning--Spain--Zaragoza.
Sustainable urban development--Spain--Zaragoza.
Harvard subject headings:
Architecture--Spain--Zaragoza--21st century.
City planning--Spain--Zaragoza.
Sustainable urban development--Spain.--Zaragoza.
Princeton subject headings:
City planning--Spain--Zaragoza.
Sustainable urban development--Spain--Zaragoza.