Columbia subject headings:
Architecture, Medieval--Italy--Grado.
Basilica di San Piero a Grado.
Grado (Italy)--Buildings, structures, etc.
Grado (Italy)--Church history.
Harvard subject headings:
Architecture, Medieval--Italy--Pisa Region--Congresses.
Basilica di San Piero a Grado.
Basilicas--Italy--San Piero a Grado.
Church architecture--Italy--San Piero a Grado.
Church decoration and ornament--Italy--San Piero a Grado.
Congresses and conventions
Peter, the Apostle, Saint--Cult--Congresses.
Pisa Region (Italy)--Buildings, structures, etc.--Congresses.
Pisa Region (Italy)--Church history--Congresses.
Princeton subject headings:
Architecture, Medieval--Italy--Grado.
Basilica di San Piero a Grado.
Grado (Italy)--Buildings, structures, etc.
Grado (Italy)--Church history.