Columbia subject headings:
Harvard subject headings:
Architecture and religion.
Architecture, Italian--Designs and plans.
Architecture, Medieval--Italy--Pisa.
Architecture--Italy--Pisa.
Architecture--Mathematics
Battistero di San Giovanni (Pisa, Italy)
Duomo (Pisa, Italy)
Leaning Tower (Pisa, Italy)
Piazza dei Miracoli (Pisa, Italy)
Princeton subject headings:
Architecture--Composition, proportion, etc.
Church architecture--Italy--Pisa.
Space (Architecture)