Columbia subject headings:
Harvard subject headings:
Architecture--Arid regions--Africa.
Architecture--Arid regions--Spain.
Building, Clay--Africa.
Building, Clay--Spain.
Vernacular architecture--Africa.
Vernacular architecture--Spain.
Princeton subject headings:
Adobe houses--Africa, Northwest.
Adobe houses--Spain.
Building, Adobe.
Vernacular architecture--Africa, Northwest.
Vernacular architecture--Spain.